Dissertations / Theses on the topic 'Movement variabiliity'

The detrimental nature of movement variability has recently been reconsidered with suggestions that it has a functional role to play in performance. Movements in golf can be attributed to the organismic, task and environmental constraints from which they emerge with these swing movements affecting shot outcomes. A three-dimensional analysis of address position variability revealed that higher skilled golfers present reduced alignment variability in angular relationships between the shoulders and stance compared to less skilled counterparts. Whilst there were no group differences in impact variability, both points in the swing displayed reducing variability from proximal to distal aspects of the kinetic chain. With the popularity of strength and conditioning growing within the golfing world it has become important for coaches to be able to assess golfers’ physical constraints. Two-dimensional analysis, representative of that used in coaching environments, assessed the relationship between the overhead squat and deterioration of posture in the golf swing. Results showed small but significant relationships between this test and golf swing postural kinematics. An 8-week intervention to address overhead squat physical constraints resulted in no change in 3D swing kinematics. Strength and conditioning as a stand-alone intervention provides no benefits to postural kinematics suggesting the need for coaching.

The aim of this programme of work was to examine how the manipulation of organismic and task constraints affected movement variability during a basketball shooting task. The specific constraints that were manipulated included task expertise, state anxiety and dioptric blur (organismic constraints), and, shooting distance and attentional focus instruction (task constraints). The aim of Study 1 was to investigate the effect of shooting distance and task expertise on movement variability. Task expertise was characterised by decreased coordination variability and heightened compensatory variability between wrist, elbow and shoulder joints. However, no significant difference was found in joint angle variability at release as a function of task expertise. There was no significant change in movement variability with shooting distance, a finding that was consistent across all expertise groups. In Study 2, the aims were to examine the effect of induced dioptric blur on shooting performance and movement variability during basketball free-throw shooting, and, to ascertain whether task expertise plays a mediating role in the capacity to stabilise performance against impaired visual information. Significant improvements in shooting performance were noted with the introduction of moderate visual blur (+1.00 and +2.00 D). This performance change was evident in both expert and novice performers. Only with the onset of substantial dioptric blur (+3.00 D), equivalent to the legal blindness limit, was there a significant decrease in coordination variability. Despite the change in coordination variability at +3.00 D, there was no significant difference in shooting performance when compared to the baseline condition. The aims of Study 3 were to examine the effect of elevated anxiety on shooting performance and movement variability and, again, to determine whether task expertise plays a mediating role in stabilising performance and movement kinematics against perturbation from emotional fluctuations. Commensurate with the results of Study 2, both expert and novice performers were able to stabilise performance and movement kinematics, this time with elevated anxiety. Stabilisation was achieved through the allocation of additional attentional resources to the task. Study 4, had two aims. The first was to examine the interactive effects of practice and focus of attention on both performance and learning of an accuracy-based, discrete multi-articular action. The second was to identify potential focus-dependent changes on joint kinematics, intra-limb coordination and coordination variability. Support was found for the role of an external focus of attention on shooting performance during both acquisition and retention. However, there was evidence to suggest that internal focus instruction could play a pivotal role in shaping emerging patterns of intra-limb coordination and channelling the learners‟ search towards a smaller range of kinematic solutions within the perceptual-motor workspace. Collectively, this programme of work consistently highlighted the fundamental role that constraints play in governing shooting performance, movement variability and, more broadly, perceptual-motor organisation. For instance, task expertise was characterised by decreased coordination variability and heightened compensatory control. However, in light of the data pertaining to joint angle variability at release, general assumptions about expertise-variability relations cannot be made and should be viewed with caution. In addition, there is strong evidence to suggest that adaptation to constraints is, perhaps, a universal human response, and consequently not mediated by task expertise. Further research is needed to fully elucidate this proposition.

Falls are the most frequent cause of unintentional injuries among older adults; afflicting 30 percent of persons aged 65 and older and more than 50 percent of persons aged 85 and older. There is a serious need for strategies to prevent falls in elderly individuals, but an important challenge in fall prevention is the paucity of objective evidence regarding the mechanisms that lead directly to falls. There exists no mechanisms about how to predict and manage elderly falls, which has multifactorial risk factors associated with its occurrence in the elderly. As the U.S. population continues to age, both the number of falls as well as the cost of treatment of fall injuries will continue to grow. Decades of research in fall prevention has not led to a decrease in the fall incidence; thus new strategies need to be introduced to understand and prevent falls. Aging reduces the adaptability of various physical and environmental stressors that hinder stability and balance maintenance and may therefore result in a fall. Movement variability in an individual's task performance can be used to assess the limitations of the movement control system. Maintaining variation in movement engenders flexible and adaptable modalities for elderly individuals to prevent falls in an unpredictable and ever changing external environment. Conversely, excessive variability of movement may drive the control system closer to its stability limits during balance and walking tasks. Accordingly, inertial sensors are an emerging wearable technology that can facilitate noninvasive monitoring of fall prone individuals in clinical settings. This research examined the potential of inertial sensors for use in clinical settings, and evaluated their effectiveness in comparison to mature laboratory systems (i.e., force platform and camera system). Study findings showed a relationship between movement variability and fall risk among healthy young and older adults. Further, the outcomes of this work translates to the clinical environment to better understand the health status (leading to frailty) of cardiac patients; reflected by the underlying adaptability of the control system, but requires further improvements if to be used as robust clinical tool. This research provides the groundwork for rapid clinical assessments in which its validity and robustness should be investigated in future efforts.
Ph. D.

Land pressures today and government policy-requires previously developed, 'brownfield' land to be brought back into beneficial use. The nature of these sites means that they may have been subject to some form of contamination from previous uses. The risk any pollutant has to human health and the environment must be assessed and, if deemed unacceptable, remediation must be undertaken. Risk assessment may be carried out utilising generic values for contaminant properties that can give misleading results. This thesis describes the effort to further assess the controls on adsorption of organic pollutants and its spatial variability. Spatial sampling of two brownfield sites was undertaken with generic soil parameters being measured. To better describe soil organic matter, organic extracts were prepared from soils, allowing NMR spectra to be collected. The collected soil dataset is analysed to discern any correlations between soil parameters. The nature of the organic pollutants used in this study (benzene, phenol, p-xylene and p-cresol) is described using calculated molecular descriptors. The variation in experimental adsorption results, provided by Sheffield University, were then statistically analysed using soil measures as predictors and then also adding molecular descriptors to the analysis. The percentage of black carbon may also have an influence on adsorption and so this was also measured and added to the list of predictors available for inclusion in stepwise regression. Results show that adsorption of these organic compounds can be partially described using the measured soil parameters. Molecular descriptors such as a molecule's surface area can also be used to predict adsorption. The percentage black carbon was an important predictor in only one instance for p-xylene adsorption. Soil parameters were also shown to be predicted by other soil variables from the dataset, giving good results that were improved upon by transforming all parameters to normality.

The purpose of this study was to examine the effects of FOA cues on movement coordination of the lower extremity during a standing long jump. A modified vector coding analysis of hip/knee and ankle/knee coordination was used to evaluate the influence of FOA cues on coordination patterns and coordination variability. Results indicated no main effect of coordination patterns between FOA conditions for ankle/knee coordination F(1,19) = 0.43, p = 0.52 or coordination variability F(1,19) = 0.00, p = 0.98 and no main effect of hip/knee coordination patterns F(1,19) = 2.48, p = 0.13 or coordination variability F(1,19) = 5.0, p = 0.49. Participants did jump significantly further under and external FOA (2.27 ± .38m) than the internal FOA (2.16 ± .37m, p = 0.035). It is possible that manipulation of arm swing coordination or landing strategies are influencing the changes in jump distances between FOA conditions.

Humans routinely make movements to targets that have different accuracy requirements in different directions. Examples extend from everyday occurrences such as grasping the handle of a coffee cup to the more refined instance of a surgeon positioning a scalpel. The attainment of accuracy in situations such as these might rest upon the nervous system's capacity to regulate the limb's resistance to displacement, or impedance. To test this idea, subjects made movements from random starting locations to targets that had shape dependant accuracy requirements. A robotic device was used to assess both limb impedance and patterns of movement variability just as the subject reached the target. Impedance was seen to increase in directions where required accuracy was high. Furthermore, independent of target shape patterns of limb stiffness were seen to predict spatial patterns of movement variability. The nervous system was thus seen to modulate limb impedance in wholly predictable environments to shape movement variability and achieve reaching accuracy.

Introduction: Movement variability can be defined as the variance in human movement from one trial or cycle to the next, often when attempting to maintain dynamic equilibrium (in the case of continuous skills) or achieve consistent movement outcome (for discrete skills). Some theoretical perspectives of motor control consider movement variability to be deleterious. However, the dynamical systems perspective proposes beneficial and functional roles for movement variability. Within this view variability has developed as an independent theme of research that has gained momentum over the past 25 years, attracting focus from various sub-disciplines within the field with a major contribution from sports biomechanics. The previous research within the field of movement variability has proposed that these functional roles include reducing the risk of injury, enabling coordination change and facilitating adaptation to varying task or environmental constraints. This thesis is primarily constituted of four sequential studies designed to further the method-related approach to, and theoretical understanding of, the interaction between variability in discrete movement and adaptation.

A study was undertaken to better understand the hydrogeologic framework of the Delaware County, Indiana. Arc View GIS 3-D and Spatial Analysts along with VISUAL MODFLOW are used to study the flow patterns by developing a 3-D model of major aquifers in the county, both glacial and bedrock. The GIS platform facilitates the time consuming task of preparing data input and output. In addition, major recharge zones are also identified in GIS using soil and slope data.The bedrock of Delaware County is composed of Silurian bedrock, which is overlain by glacial drift. The drift is mostly till that is interbedded with eight sand and gravel layers which are horizontal and discontinuous. Both, bedrock and sand & gravel glacial aquifers are good sources of groundwater in the county. More than 3000 water wells are located in the area. It is very interesting to note that 50% of the water-wells in the area are in confined sand and gravel and the remaining wells are in carbonaceous bedrock. The bedrock contains numerous preglacial karsts valley systems which are areas of high transmissivity solution features, also adding further interest to modeling this region.The hydraulic conductivity of sand and gravel is assumed to be 0.0015 m/s whereas for bedrock 0.00025 m/s is used. The streambeds in the area are also the source of groundwater discharge. The hydraulic conductivity of streambed is equal to 0.00028 m/s. Recharge to the area occurs as net recharge, which varies spatially depending on the nature of soil.Several simplifying assumptions were made for the conceptualization and simulation of flow in the basins. The main assumptions are as follows: 1) groundwater is in steady-state, 2) pumping does not significantly affect the level of hydraulic heads; therefore only high capacity pumping wells are simulated, 3) Net recharge from precipitation varies spatially, 4) flow in the bedrock aquifer occurs in the uppermost 40 m and is horizontal 5) vertical flow is assumed to be controlled by intervening sand and gravel units. Ground-water flow in the basins was conceptualized as a three-dimensional flow system. The model boundaries selected to represent natural hydrologic boundaries include (1) river leakage boundaries along major rivers; (2) a constant head boundary around the aquifer boundaries; (3) a general head boundary along the major streams; (4) drain boundaries along major drains; and 5) Evapotranspiration losses.The simulated region is an area of 398 square miles. The model consists of over 3600 cells and employed a regular grid spacing of 6o x 60. A variable grid was designed to provide additional detail in areas of special interest and thus allowed these areas to be simulated more accurately in the model.The model was calibrated using a manual trial-and-error adjustment of parameters. Hydraulic conductivity values, and streambed conductance were adjusted during successive simulations until the flow pattern matches the regional flow direction as computed from the water-well derived (static water level) potentiometric surface. The computed potentiometric surface is an adequate or reasonable match on a regional scale, with the general trend of SE-NW. It is observed that the model is extremely sensitive to changes in horizontal hydraulic conductivity and recharge in the form of precipitation. The model is least sensitive to streambed vertical hydraulic conductivity.The water budget for the calibrated model represents the distribution of groundwater inflow and outflow during calibration. The data indicate that 16.5% of the inflow to the modeled groundwater system is flow across model boundaries and 83% from effective recharge from precipitation, and the rest from streams and rivers. Outflow consists of 2% pumpage, 5% seepage to streams and drains, and 93% is flow across boundaries.It is expected that this study will be beneficial to improve the understanding of groundwater in Delaware County, including both vertical and horizontal flow and interaction of flow between surface and groundwater. Also, the results of the modeling study can be used as a predictive tool for long-term management and monitoring of water resources in the region.
Department of Geology

The overarching aim of this programme of work was to evaluate the effectiveness of the existing learning environment within the Australian Institute of Sport (AIS) elite springboard diving programme. Unique to the current research programme, is the application of ideas from an established theory of motor learning, specifically ecological dynamics, to an applied high performance training environment. In this research programme springboard diving is examined as a complex system, where individual, task, and environmental constraints are continually interacting to shape performance. As a consequence, this thesis presents some necessary and unique insights into representative learning design and movement adaptations in a sample of elite athletes. The questions examined in this programme of work relate to how best to structure practice, which is central to developing an effective learning environment in a high performance setting. Specifically, the series of studies reported in the chapters of this doctoral thesis: (i) provide evidence for the importance of designing representative practice tasks in training; (ii) establish that completed and baulked (prematurely terminated) take-offs are not different enough to justify the abortion of a planned dive; and (iii), confirm that elite athletes performing complex skills are able to adapt their movement patterns to achieve consistent performance outcomes from variable dive take-off conditions. Chapters One and Two of the thesis provide an overview of the theoretical ideas framing the programme of work, and include a review of literature pertinent to the research aims and subsequent empirical chapters. Chapter Three examined the representativeness of take-off tasks completed in the two AIS diving training facilities routinely used in springboard diving. Results highlighted differences in the preparatory phase of reverse dive take-offs completed by elite divers during normal training tasks in the dry-land and aquatic training environments. The most noticeable differences in dive take-off between environments began during the hurdle (step, jump, height and flight) where the diver generates the necessary momentum to complete the dive. Consequently, greater step lengths, jump heights and flight times, resulted in greater board depression prior to take-off in the aquatic environment where the dives required greater amounts of rotation. The differences observed between the preparatory phases of reverse dive take-offs completed in the dry-land and aquatic training environments are arguably a consequence of the constraints of the training environment. Specifically, differences in the environmental information available to the athletes, and the need to alter the landing (feet first vs. wrist first landing) from the take-off, resulted in a decoupling of important perception and action information and a decomposition of the dive take-off task. In attempting to only practise high quality dives, many athletes have followed a traditional motor learning approach (Schmidt, 1975) and tried to eliminate take-off variations during training. Chapter Four examined whether observable differences existed between the movement kinematics of elite divers in the preparation phases of baulked (prematurely terminated) and completed take-offs that might justify this approach to training. Qualitative and quantitative analyses of variability within conditions revealed greater consistency and less variability when dives were completed, and greater variability amongst baulked take-offs for all participants. Based on these findings, it is probable that athletes choose to abort a planned take-off when they detect small variations from the movement patterns (e.g., step lengths, jump height, springboard depression) of highly practiced comfortable dives. However, with no major differences in coordination patterns (topology of the angle-angle plots), and the potential for negative performance outcomes in competition, there appears to be no training advantage in baulking on unsatisfactory take-offs during training, except when a threat of injury is perceived by the athlete. Instead, it was considered that enhancing the athletes' movement adaptability would be a more functional motor learning strategy. In Chapter Five, a twelve-week training programme was conducted to determine whether a sample of elite divers were able to adapt their movement patterns and complete dives successfully, regardless of the perceived quality of their preparatory movements on the springboard. The data indeed suggested that elite divers were able to adapt their movements during the preparatory phase of the take-off and complete good quality dives under more varied take-off conditions; displaying greater consistency and stability in the key performance outcome (dive entry). These findings are in line with previous research findings from other sports (e.g., shooting, triple jump and basketball) and demonstrate how functional or compensatory movement variability can afford greater flexibility in task execution. By previously only practising dives with good quality take-offs, it can be argued that divers only developed strong couplings between information and movement under very specific performance circumstances. As a result, this sample was sometimes characterised by poor performance in competition when the athletes experienced a suboptimal take-off. Throughout this training programme, where divers were encouraged to minimise baulking and attempt to complete every dive, they demonstrated that it was possible to strengthen the information and movement coupling in a variety of performance circumstances, widening of the basin of performance solutions and providing alternative couplings to solve a performance problem even when the take-off was not ideal. The results of this programme of research provide theoretical and experimental implications for understanding representative learning design and movement pattern variability in applied sports science research. Theoretically, this PhD programme contributes empirical evidence to demonstrate the importance of representative design in the training environments of high performance sports programmes. Specifically, this thesis advocates for the design of learning environments that effectively capture and enhance functional and flexible movement responses representative of performance contexts. Further, data from this thesis showed that elite athletes performing complex tasks were able to adapt their movements in the preparatory phase and complete good quality dives under more varied take-off conditions. This finding signals some significant practical implications for athletes, coaches and sports scientists. As such, it is recommended that care should be taken by coaches when designing practice tasks since the clear implication is that athletes need to practice adapting movement patterns during ongoing regulation of multi-articular coordination tasks. For example, volleyball servers can adapt to small variations in the ball toss phase, long jumpers can visually regulate gait as they prepare for the take-off, and springboard divers need to continue to practice adapting their take-off from the hurdle step. In summary, the studies of this programme of work have confirmed that the task constraints of training environments in elite sport performance programmes need to provide a faithful simulation of a competitive performance environment in order that performance outcomes may be stabilised with practice. Further, it is apparent that training environments can be enhanced by ensuring the representative design of task constraints, which have high action fidelity with the performance context. Ultimately, this study recommends that the traditional coaching adage 'perfect practice makes perfect", be reconsidered; instead advocating that practice should be, as Bernstein (1967) suggested, "repetition without repetition".

Context: This thesis focused on two main areas of golf performance. Firstly, centre of pressure excursions influence on full golf swing performance, as despite golf coaching literature placing importance on weight transfer, literature into this mechanism is limited. Secondly, the area of the golf putt was examined; few studies have investigated the biomechanics into the putting stroke despite it being identified as the most important performance factor within golf. Areas of investigation were, centre of pressure excursions during the putting stroke, the impact point on golf ball and movement variability on performance outcomes being the ball roll kinematics. Aims: To examine biomechanical factors that influence golf performance. Centre of pressure excursion during the full golf swing and putting stroke were examined. Additionally, body segment kinematics and variability of rotations were correlated with putting performance outcomes. The impact point on the golf ball was considered as a mechanism that can cause variability of the kinematic ball roll. Subjects: All subjects used in this thesis were actively playing golf. Subjects were categorised using the golf handicap system. For studies assessing reliability, validity or isolating putter stroke kinematics a mechanical putting robot was used. Methods: Correlational research whereby no variables were manipulated was predominantly adopted throughout this thesis to establish relationships between biomechanical parameters and golf performance. Biomechanical parameters were assessed using the appropriate data collection and analysis techniques; this included the variability associated with segment rotations. Results: Significant differences were observed for the centre of pressure excursions along the mediolateral axis between three different golf clubs (full swing). For the putting stroke low handicap golfers demonstrated lower centre of pressure excursions along the anteroposterior axis in comparison to high handicap golfers, additionally, a large amount of inter-subject variability was observed for centre of pressure excursions. In regards to the impact point on the golf ball, significant associations were identified between impact variables and the performance measures horizontal launch angle and whether the ball was pushed or pulled, these results were not replicated with human participants. It was identified that the relationship between the centre of mass displacement and centre of pressure excursions is a complex one and that movement variability had a detrimental effect on the horizontal launch angle and therefore performance. Conclusions: The results from the full swing analysis of this thesis suggest that stance width may influence the amount of centre of pressure excursions that occur. For the golf putting stroke, golfers and coaches should reduce the amount of variability associated with the technique to improve performance. Regarding future scientific research, a combination of individual analysis accompanying group-based analysis should be utilised due to the large inter-subject differences observed.

Marine Protected Areas (MPA) are broadly used to protect marine ecosystems, restore biomass, and increasingly as tools in fisheries management for benthic stocks. Nevertheless, MPAs are seldom used to target pelagic species due the challenges of designing an effective MPA in a highly dynamic environment. It is believed that highly mobile organisms will get few benefits, since they leave the protected area too frequently. One possible solution is to compensate for such movement with larger MPAs. Nevertheless, uncertainty about the benefits in the face of vagaries about fish movement make it unlikely that such efforts would be successfully pursued.

Although it is a generally accepted that MPAs provide multiple benefits if well designed, empirical demonstrations of benefits from MPA are hard to obtain. They require long term evaluations, and as a consequence, comparisons between alternative MPA designs are almost nonexistent. Simulation models provide an alternative to empirical approaches that allow tests of designs and forecasts of potential outcomes. To date, most of the simulation models of MPAs have been developed for benthic systems, where simplified assumptions about fish and fisherman movement are reasonable. Fortunately, with the advent of more realistic fish movement models, new approaches are now possible that can combine complex individual-based models of movement, population dynamics and virtual MPA systems. The use of these new complex simulation models can guide the optimization of MPA design to increase both stock sizes and fisheries yields.

The goal of the research presented in this dissertation is to study the potential of a large MPA to protect a pelagic stock and determine how fish movement characteristics and complex environmental dynamics influence the optimal design criteria for a successful pelagic MPA. The findings are timely given increasing interest in developing large no fishing zones to protect overfished pelagic stocks, especially for those taxa whose distribution spans more than one exclusive economic zone or resides in international waters. For this purpose I implemented a simulation model that incorporates detailed fish movement and their responses to complex environmental forcing to study the effect of fish movement on the efficacy of MPAs of different size and location. (Abstract shortened by ProQuest.)

Species’ ranges arise from the interplay between environmental preferences, biotic and abiotic environmental conditions, and accessibility. Understanding of – and predictive models on – species distributions often build from the assumption that these factors apply homogenously within each species, but there is growing evidence for individual variation. Here, I use movement data to investigate individual-level decisions and compromises regarding the different costs and benefits influencing individuals’ geographic locations, and the species-level spatial patterns that emerge from these. I first developed a new method that uses tracking data to quantify individual specialisation in geographic space (site fidelity) or in environmental space (environmental specialisation). Applying it to two species of albatrosses, I found evidence of site fidelity but weak environmental specialisation. My results have implications for how limited research efforts are best-targeted: if animals are generalists, effort are best spent by understanding in depth individual patterns, i.e., better to track fewer individuals for long periods of time; whereas if animals tend to be specialists, efforts should be dedicated to tracking as many individuals as possible, even if for shorter periods. I then investigated individual migratory strategies and their drivers in nine North American bird species, using ringing/recovery data. I found latitudinal redistribution of individuals within the breeding and non-breeding ranges that generally did not follow textbook patterns (‘chain migration’ or ‘leapfrog migration’). Migratory individuals tend to trade off the benefits of migration (better tracking of climatic niche; better access to resources) and its costs (increasing with migratory distance). I found that birds are more likely to remain as residents in areas with warmer winter temperatures, higher summer resource surpluses and higher human population densities (presumably because of a buffering effect of urban areas). Overall, my results highlight the importance of considering individual variation to understanding the ecological processes underpinning species’ spatial patterns.

In sports, accuracy is an essential component of actions such passing, shooting, and aiming. Executing a movement or action that requires a high degree of accuracy is a critical determinant of success in many individual and team sports. Each sport has different methods for evaluating accuracy, however an overarching goal is to determine whether an object hits its target, or assess the distance by which it misses. However, in some sports accuracy is not readily measureable because an object might not reach a target, i.e. the object is intercepted, or it collides with another object or a person, or an endpoint might not be visible. One example of this is the badminton serve, where the shuttlecock is normally hit by a receiving player before it reaches the ground, its intended endpoint. The goal of one common serve type, the short serve, is to force the opponent into hitting the shuttlecock upward at a steep angle in order to clear the net, allowing a serving player to hit the shuttlecock from a point high above the net from which it is easier to score. The optimal trajectory of the short serve, therefore, is one in which the apex occurs before the shuttlecock crosses the net and results in a steep downward trajectory. To accomplish this, the swing trajectory of the racquet must be accurate itself, which is usually accomplished by use of a short period of swing (i.e. swing length). In practice the analysis of both swing technique and shuttlecock trajectory is usually done subjectively (by the coach), however objective quantification is necessary in order to determine the shuttlecock trajectories and racquet swing techniques that provide the best serve result to allow correct representation of serve accuracy. The main issue is that an objective measurement is needed, and since the shuttlecock doesn’t land on the ground, it makes it difficult to determine serve accuracy with the existing protocols. The broad aims of this Master’s thesis were to (i) develop a new method of measuring accuracy of the short serve;(ii) compare and contrast the technique/s of elite badminton players using principal component analysis; and, (iii) determine the magnitude of variability in the movement patterns of elite players performing the short serve. In the first study (Study I), a specific definition of accuracy was presented that allowed assessment when the endpoint is not reached (i.e. when the shuttlecock does not land on the court). The accuracy of an object’s trajectory is typically evaluated by determining whether it hits a target, or measuring the distance by which it misses. For the badminton short serve, the rules dictate that the shuttlecock must land on or beyond the service line (1.98 m from the net) after traversing the net. However these constraints are insufficient to distinguish poor from good serves; a serve where the shuttlecock clears the net by a small margin but continues and does not reach its apex until after it passes the net might be considered poorer in accuracy (easier for receiver to return) than one in which the shuttlecock reaches its apex before the net even if its height over the net is greater. In this study, short serve trajectories were recorded with and without a receiver present. Two separate data collection sessions and 13 players were tested across both sessions (Session A and B) (age: 23.4 ± 5.1 years, body mass: 73.2 ± 11.1 kg, height: 175 ± 8.6 cm). Data from trials with full trajectory (without an opponent) were used to create a model enabling the prediction of shuttlecock landing. This model was then used to predict the shuttlecock landing point in trials with a receiver, with an important finding being that 69% of serves would have landed on or short of the service line. Thus, receivers might benefit from leaving a majority of serves in competition in order to win the point; servers make the assumption that receivers will return most serves and therefore choose to serve short. Using the new accuracy method, serve accuracy was categorised as accurate, inaccurate, apex good, and clearance good. This provided individual and group accuracy ratings. In Study II a three-dimensional model was developed to examine the upper body kinematics during the badminton short serve. Textbook definitions hold that push-like movement patterns produce trajectories of the highest accuracy, however reducing complexity (i.e. degrees of freedom) is also stated as essential. Nonetheless, these patterns may be mutually exclusive, since push-like patterns may exhibit considerable complexity. The purpose of Study II was to describe the short serve movement patterns used by elite badminton players to determine whether push-like or low-complexity (or both) patterns predominate. Eight participants were recruited from the Senior Australian National Doubles Badminton squad (mean age: 23.4 ±5.1 years, body mass: 73.2 ±11.1 kg, height: 175 ±8.6 cm). Three-dimensional kinematics were measured with an opponent present and analysed using principal component analysis to determine what movement patterns were used in this accuracy-based skill. Results showed that all players adopted a push-like movement pattern, but the most accurate servers also constrained the number of degrees of freedom by allowing movements of the elbow and wrist joints only in a single plane. The main objective of Study III was to understand the role that movement variability plays in a precision-based movement. Little research has been published examining movement variability in sports, specifically in skills that require accuracy. The badminton short serve provided a unique opportunity to examine how elite athletes vary their movement patterns, since it requires precise multi-joint coordination to achieve an accurate serve. Recent research has shown that a rigid or inflexible system may not be good for performance and that it is more appropriate to understand the adaptability of a movement in an ever-changing environment. A three-dimensional motion analysis of eight elite badminton players performing30 short serves with an opponent present to replicate match condition s was conducted. The results identified that players incorporate variability in specific phases of their movements reduce variability at racquet-shuttlecock contact. Higher medio-lateral (transverse plane) variability was displayed in most joint angles across all players. This strategy incorporated variability in the task-redundant dimension (transverse) to reduce variability in the task-relevant dimension (sagittal), which directly impact accuracy of the serve. Variability was also present in the timing of the swing itself, varying the timing of the backswing to reduce the variability at the contact point was a common feature displayed across all subjects, irrespective of whether the serve was accurate or not. Findings suggest elite badminton players use joint and timing variability in a functional capacity. In conclusion, the methods developed to analyse the accuracy and kinematics of an accuracy-based task such as the badminton short serve revealed a greater insight into what defines an accurate serve, and how elite players coordinate and vary their movement to achieve accuracy. The results from Study I suggest that training either with an opponent present or serving on or slightly short of the service line may lead to better serve performance. The results from Study II provide the coach or player with information on the ideal movement patterns for short serve accuracy i.e. reducing the number of degrees of freedom involved (i.e. reduce movement complexity), using a push-like movement, and paying close attention to the movement from the elbow and wrist joints. The final study (Study III) revealed that elite badminton players vary their movement in a plane (transverse) that has less impact on the outcome of the task, thus reducing the variability in the plane (sagittal) that has the larger impact on the serve movement.

There is extensive evidence that movements are prepared prior to their release. Transcranial magnetic stimulation, and in particular the motor evoked potential produced when stimulating over the primary motor cortex, has given a great deal of insight into the processes involved in preparation for voluntary movements. The excitability of the primary motor cortex remains in a state of dynamic fluctuation even when in the “resting” state, with the TMS MEP being exquisitely sensitive to this as evidenced by its tremendous trial to trial variability. Interestingly there is growing body of evidence to suggest that modulation of signal noise can provide insight into biological processes including movement preparation – indeed the output of the corticospinal tract would logically need to adapt to resting variability to enable the precise reproduction of movements. While much of the TMS literature has addressed MEP variability as a “noisy” signal, this thesis aims to assess whether elements of this “noise” can be utilized as a marker of biologic process during the reaction time period for simple human finger movements. Through successive chapters we demonstrate that the variability of corticospinal tract output, as evidenced by the TMS MEP, declines during the process of preparation for simple human finger movements. We demonstrate that the reaction time decline in variability is focal to muscles directly involved in the task. Furthermore, the rate of decline in MEP amplitude variability during the reaction time period appears intimately linked to the speed of movement initiation. Additionally, the changes we see here precede changes in mean excitability in agonists, and indeed are seen to be associated with a decline in mean excitability when surround muscles are tasked with deliberate inactivity. Finally, observations in stroke patients suggest an alteration in variability control during movement preparation and appear to be associated with concordant changes in task performance.

El entrenamiento de la fuerza en los deportes de equipo ha ido evolucionando en las últimas décadas hacia un enfoque más integrador, adaptándose a sus características propias y distanciándose de los entrenamientos más tradicionales derivados de los deportes individuales. Julio Tous (Seirul·lo, 2017, Capítulo Tous Fajardo, Julio) propone un cambio de paradigma basando el entrenamiento de fuerza en el movimiento humano, así serán los movimientos los que actuarán como eje vertebrador de las propuestas de ejercicios de fuerza y no los grupos musculares, que serán los meros ejecutores. Una de las metodologías que nos permiten ajustarnos a este cambio de paradigma es el entrenamiento estructurado a través de sus diferentes niveles de aproximación deportiva. Seirul·lo (Seirul-lo, 1993b) estableció cuatro niveles de especificidad que iban de general a competitivo; posteriormente, Moras (1994) estableció seis niveles de aproximación deportiva que iban del 0 al 5 y sus diferentes agrupaciones. Uno de los grandes retos pendientes de abordar y aportar evidencia científica era mediante qué sensores y a través de qué tipo de análisis se debían monitorizar estos niveles de aproximación deportiva, especialmente en ese cambio de ejercicios con una predominancia condicional a otros con predominancia coordinativa. Desde una perspectiva de evaluación, las oscilaciones del movimiento humano se pueden evaluar como cualquier otra serie temporal (Couceiro et al., 2014). Sin embargo, las series temporales fruto de señales fisiológicas presentan fluctuaciones no lineales y, como consecuencia, realizar un análisis estadístico mediante técnicas lineales nos dará como resultado una información parcial del movimiento humano (Orellana & Torres, 2010). Por lo tanto, el uso de herramientas no lineales como la entropía puede ser una buena alternativa para explorar la naturaleza del movimiento humano y su relación con el desarrollo coordinativo (Preatoni et al., 2013), reflejando cambios en la variabilidad de movimiento durante la ejecución de las tareas y a lo largo del tiempo. Así, el objetivo de esta tesis fue analizar el rol de la variabilidad de movimiento medida a través de la entropía en tareas de fuerza con diferentes niveles de aproximación deportiva. Primero se hizo una prueba piloto con el objetivo de comprobar si los acelerómetros de dos sensores con frecuencias de muestreo de 100 y 1000Hz eran válidos para evaluar tareas de fuerza de corta duración seleccionados en los estudios de esta tesis. Se observaron que había diferencias tanto en los valores de aceleración media como de entropía en base a la frecuencia de muestreo, con valores de entropía significativamente superiores al registrar a 100 Hz, donde claramente se observaba que había una pérdida de puntos temporales los cuales hacían que la señal fuera menos previsible (Figura 11). En conclusión, dadas las características temporales de las tareas de fuerza en los deportes de equipo, 1000 Hz es una frecuencia adecuada para registrar los ejercicios cortos y explosivos, y por lo tanto fue la frecuencia empleada durante todos los estudios de la tesis. En el primer estudio se analizó la variabilidad en la aceleración durante una tarea de fuerza realizada con un cono de inercia sin (NOBALL) y con (BALL) el condicionante de coger y pasar un balón de rugby. Cambios en las medias (%; ± 90% CL) de 4.64; ± 3.1 g en la aceleración media y 39.48; ± 36.63 a.u. en la entropía indican un aumento probable y muy probable cuando se introduce el condicionante del balón. La entropía multiescala también mostró una mayor imprevisibilidad de la aceleración bajo la condición del balón, especialmente en escalas de tiempo más altas. Por lo tanto, la aplicación de condicionantes coordinativos en el entrenamiento de fuerza con jugadores de rugby produce una cantidad diferente de variabilidad de movimiento a través de múltiples escalas de tiempo fisiológico. El segundo estudio tuvo como objetivo identificar las diferencias entre posiciones (forwards vs. backs) en la variabilidad del movimiento en el entrenamiento de placajes acumulados durante los roles de ataque y defensa. Los participantes realizaron cuatro bloques de seis placajes de defensa (es decir, placar a un oponente) y seis de ataque (es decir, ser tacleado por un oponente mientras llevaba una pelota), es decir, 48 placajes totales. Se utilizó la entropía muestral (SampEn) para analizar la variabilidad del movimiento. Se observaron diferencias significativas entre bloques en los backs (bloque 1 frente a 3 y bloque 1 frente a 4 pero no en forwards. La variabilidad del movimiento mostró una reducción progresiva con los placajes acumulados, especialmente en los backs y en el rol defensivo. Los delanteros presentaron valores de variabilidad de movimiento más bajos en todos los bloques, particularmente en el primero, tanto en el rol de ataque como en el defensa. Por último, el tercer estudio el objetivo fue identificar los cambios en la variabilidad de movimiento y la velocidad de ejecución durante un período de entrenamiento de seis semanas utilizando una tarea de fuerza realizada con un cono inercial sin (NOBALL) y con (BALL) el condicionante de coger y pasar una pelota de rugby, durante un período de seis semanas. SampEn no mostró una disminución significativa para NOBALL (ES -0.64 ± 1.02) y una disminución significativa para BALL (ES -1.71 ± 1.16; p <0.007). Además, la velocidad de ejecución mostró un aumento significativo para NOBALL (ES 1.02 ± 1.05; p <0.047), y un aumento significativo para BALL (ES 1.25 ± 1.08; p <0.025) entre las semanas 1 y 6. El índice de complejidad mostró mayores niveles en la condición de BALL, especialmente en las primeras tres semanas. La velocidad de ejecución y la variabilidad de movimiento se adaptaron a las limitaciones de la tarea después de un período de entrenamiento de cuatro semanas. Las medidas de entropía parecen una técnica de señal de procesamiento de datos prometedora para identificar cuándo se deben cambiar estas tareas de ejercicio en el entrenamiento de fuerza en los deportes de equipo. En conclusión, analizar la variabilidad de movimiento a través de la entropía tendrá un rol fundamental en el control y programación de tareas de fuerza en los deportes de equipo, especialmente cuando estas tengan una predominancia coordinativa basada en el movimiento deportivo.
Over the last decades, resistance training in team sports has evolved towards a more integrative approach, adapting to its own characteristics and distancing itself from the more traditional training derived from individual sports. Based on human movement, Julio Tous (Seirul·lo Vargas, 2017, Chapter Tous Fajardo, Julio) proposed a paradigm shift in which movements act as the backbone of exercise selection instead of the muscle groups, which in turn become mere executors. Structured training is a resistance training methodology that allows us to adjust to this paradigm shift through different levels of sports approach. Seirul·lo (1993) established four levels of specificity ranging from general to competitive. Subsequently, Moras (2000) developed six levels of sports approach, ranging from zero to five with different groupings. Analysis of human movement has evolved to allow the assessment of the variability of a measure by targeting the detection of changes in fluctuations and spatiotemporal characteristics of the outcomes. Within the past 20 years, entropy analysis has become relatively popular as a measure of system complexity. Thus, the aim of this thesis was to analyse the role of movement variability measured through entropy in resistance training in team sports with different levels of sports approach. First, a pilot test was carried out to compare the values of mean acceleration and entropy values in short actions (i.e. collisions) when registered with two devices with different accelerometer sampling frequencies (1000 Hz versus 100 Hz). Differences were observed for mean acceleration and entropy when measured with different sampling frequencies. Therefore, 1000 Hz was selected as the sampling frequency for the rest of the experiments on this thesis. The first study described the variability in acceleration during a resistance training task, performed in horizontal inertial flywheels without (NOBALL) or with the constraint of catching and throwing a rugby ball (BALL). Mean changes (%; ±90%CL) of 4.64; ±3.1 g for mean acceleration and 39.48; ±36.63 a.u. for sample entropy indicated likely and very likely increase when in BALL condition. Multiscale entropy also showed higher unpredictability of acceleration under the BALL condition, especially at higher time scales. Thus, the application of match specific constraints in resistance training for rugby players elicit different amount of variability of body acceleration across multiple physiological time scales. The second study aims to identify between-position (forwards vs. backs) differences in movement variability in cumulative tackle events training during both attacking and defensive roles. Participants performed four blocks of six tackling (i.e. tackling an opponent) and six tackled (i.e. being tackled by an opponent while carrying a ball) events (i.e. 48 total tackles) while wearing a micro-technological inertial measurement unit. Sample entropy (SampEn) were used to analyse the movement variability. Significant between-block differences were observed in backs (block 1 vs 3 and block 1 vs 4) but not in forwards. Movement variability shows a progressive reduction with cumulative tackle events, especially in backs and the defensive role. Forwards present lower movement variability values in all blocks, particularly in the first block, both in the attacking and defensive role. Last, in the third study aims was to identify the changes in movement variability and movement velocity during six weeks training period using a resistance horizontal forward-backward task without (NOBALL) or with (BALL) the constraint of catching and throwing a rugby ball in the forward phase, during a six-week period. SampEn showed no significant decrease for NOBALL (ES -0.64 ± 1.02) and significant decrease for BALL (ES -1.71 ± 1.16; p<0.007) conditions. Additionally, movement velocity showed significant increase for NOBALL (ES 1.02 ± 1.05; p<0.047), and significant increase for BALL (ES 1.25 ± 1.08; p<0.025) between weeks 1 and 6. The complexity index showed higher levels of complexity in BALL condition, specifically in the first three weeks. Movement velocity and complex dynamics were adapted to the constraints of the task after a four-week training period. Entropy measures seem a promising processing signal technique to identify when these exercise tasks should be changed. In conclusion, analysing the movement variability through entropy will have a fundamental role in the control and programming of resistance training in team sports, especially when they have a coordinative predominance based on sports movement.

Background Although trainers and athletes consider ‘good timing skills’ to be critical for optimal sport performance, little is known in regard to how sport-specific skills may benefit from timing training. Thus, assuming that all motor performances are mediated by an internal timing mechanism, enhanced motor timing is expected to have positive effects on both planning and execution of movement performance, and consequently on complex sports actions as golf or soccer. Accordingly, in order to increase our knowledge of the importance of motor timing and possible effects of timing training, this thesis examines the effects of synchronized metronome training (SMT), thought to improve the execution of motor programs and to enhance motor skills in golf and soccer players. Methods Study I examined the effects of SMT on motor timing abilities and its potential effect on golf shot accuracy and consistency in 25 experienced male golfers. Additionally, Study II examined the effects of SMT on the spatiotemporal movement organisation and dynamics of the golf swing performance, as captured by kinematic measurements and analyses in thirteen male golfers. Study III examined the effect of SMT on accuracy and variability in a soccer specific, cross-pass task in elite and sub-elite female soccer players. Moreover, the underlying brain activity was assessed by means of functional magnetic resonance imaging (fMRI) to investigate the corresponding neural activity when passively observing the cross-pass task, and the possible pre- to post training effects. Results SMT was shown to improve motor timing ability, by means of less timing asynchrony and with associated changes in timing variability, in both golf- and soccer-players. Additionally, significant improvements in golf shot and soccer cross-pass performance, by means of significant increase in outcome accuracy combined with a decrease in outcome variability was found. From the kinematic investigation in Study II, results indicate that improved motor timing, as an effect of SMT, lead to a more coordinated and dynamic swing performance, and with decreased variability in the temporal structure of the swing motion. Finally, it was found that SMT induces changes in the activity of the action observation network (AON), underpinning action observation and action prediction, by means of decreased activation within bilateral cerebellum, fusiform gyrus and superior temporal gyrus. These findings hint at a more efficient pattern of neural recruitment during action observation, after SMT. Conclusion In summary, this thesis provides evidence that four weeks of SMT improved the participant’s motor timing and synchronization abilities, and showed influence on both behavioral and neurophysiological motor programs and skill performance in golf and soccer players. Thus, by improved outcome accuracy and decreased variability, affecting the coordinated movement pattern and organisation, as well as affecting the associated underlying brain activation.

Pluvial floods are formed directly from surface runoff after extreme rain events. Urban areas are prone to suffer from these floods due to large portions of hardened surfaces and limited capacity in the stormwater infrastructure. Previous research has shown that catchment response is influenced by the spatio-temporal behaviour of the rainstorm. A rainstorm moving in the same direction as the surface flow can amplify the runoff peak and temporal variability of rainfall intensity generally results in greater peak discharge compared to constant rainfall. This research attempted to relate the effect of storm movement on flood propagation in urban pluvial flooding to the effect from different distributions of rainfall intensity. An additional objective was to investigate the flood response from recent findings on the temporal variability in Swedish rain events and compare it to the flood depths produced by a CDS-rain (Chicago Design Storm), where the latter is the design practice in flood modelling today. A 2D surface model of an urban catchment was coupled with a 1D model of the drainage network and forced by six different hyetographs. Among them were five empirical hyetographs developed by Olsson et al. (2017) and one a CDS-rain. The rainstorms were simulated to move in different directions: along and against the surface flow direction, perpendicular to it and with no movement. Maximum flood depth was evaluated at ten locations and the model results show that storm movement had negligible effect on the flood depths. The impact from the movement was likely limited by the big difference in speed between the rainstorm and the surface flow. All evaluated locations showed a considerable sensitivity to changes in the hyetograph. The maximum flood depth increased at most with a factor of 1.9 depending on the hyetograph that was used as model input. The CDS-rain produced higher flood depths compared to the empirical hyetographs, although one of the empirical hyetographs produced a similar result. Based on the results from this case study, it was concluded that storm movement was not as critical as the temporal variability of rainfall when evaluating maximum flood depth.
Pluviala översvämningar skapas från ytavrinning vid intensiva nederbördstillfällen. De uppstår ofta i urbana miljöer till följd av den höga andelen hårdgjorda ytor och ledningsnätets begränsade kapacitet. Forskning har visat att ett regnmolns rörelseriktning och hastighet påverkar avrinningsförloppet. Om molnet rör sig längs med flödesriktningen i terrängen kan en ökning i vattenlödet nedströms ett avrinningsområde uppstå. Denna effekt har visat sig vara störst om hastigheten hos regnmolnet och vattenflödet är likvärdiga. Ytterliggare en faktor som påverkar avrinningsförloppet är hur regnintensiteten är fördelad över tid. Olsson et al. (2017) har tagit fram fem empiriska regntyper som speglar tidsfördelning inom ett Svenskt regntillfälle. Inom översvämningsmodellering är det vanligt att använda ett så kallat CDS-regn (Chicago Design Storm), vilken har en given tidsfördelning. Med anledning av detta är det intressant att jämföra översvämningar genererade av ett CDS-regn och av de empiriska regntyperna. Syftet med denna studie var att utreda hur regnmolns rörelse påverkar urbana pluviala översvämningar med avseende på vattendjup, samt att jämföra denna påverkan med effekten från olika tidsfördelningar av regnintensiteter. En kombinerad dagvattenmodell (1D) och markavrinningsmodell (2D) av en mindre svensk tätort användes för att simulera olika regnscenarier. De fem empiriska regntyperna och ett CDS-regn simulerades med en rörelseriktning längs med, emot och vinkelrätt i förhållande till flödesriktningen. Även scenarier med stationära regnmoln simulerades. Maximala översvämningsdjup utvärderades i tio punkter spridda över hela modellområdet. Resultatet från simuleringarna visade att regnmolnets rörelse hade försumbar påverkan på översvämningsdjupen. De olika tidsfördelningarna av regnintensitet hade däremot betydande påverkan på de maximala översvämningsdjupen. Som mest var det det maximala översvämningsdjupet 1.9 gånger större beroende vilken regntyp som användes som indata. CDS-regnet genererade i regel de största översvämningsdjupen, även om utfallet från en av de fem empiriska regntyperna var förhållandevis likvärdigt. Regnintensitetens tidsfördelning var därmed en kritisk parameter vid den hydrauliska modelleringen av urbana pluviala översävmningar, till skillnad från molnrörelse som hade försumbar påverkan.

Speed-accuracy tradeoffs, velocity profiles, and physiological tremor are fundamental characteristics of human movement. The principles underlying these phenomena have long attracted major interest and controversy. Each is well established experimentally but as yet they have no common theoretical basis. It is proposed that these three phenomena occur as the direct consequence of a movement response planning system that acts as an intermittent optimal controller operating at discrete intervals of ~100 ms. The BUMP model of response planning describes such a system. It forms the kernel of adaptive model theory which defines, in computational terms, a basic unit of motor production or BUMP. Each BUMP consists of three processes: (i) analysing sensory information, (ii) planning a desired optimal response, and (iii) executing that response. These processes operate in parallel across successive sequential BUMPs. The response planning process requires a discrete time interval in which to generate a minimum acceleration trajectory of variable duration, or horizon, to connect the actual response with the predicted future state of the target and compensate for executional error. BUMP model simulation studies show that intermittent adaptive optimal control employing two extremes of variable horizon predictive control reproduces almost exactly findings from several authoritative human experiments. On the one extreme, simulating spatially-constrained movements, a receding horizon strategy results in a logarithmic speed-accuracy tradeoff and accompanying asymmetrical velocity profiles. On the other extreme, simulating temporally-constrained movements, a fixed horizon strategy results in a linear speed-accuracy tradeoff and accompanying symmetrical velocity profiles. Furthermore, simulating ramp movements, a receding horizon strategy closely reproduces experimental observations of 10 Hz physiological tremor. A 100 ms planning interval yields waveforms and power spectra equivalent to those of joint-angle, angular velocity and electromyogram signals recorded for several speeds, directions, and skill levels of finger movement. While other models of response planning account for one or other set of experimentally observed features of speed-accuracy tradeoffs, velocity profiles, and physiological tremor, none accounts for all three. The BUMP model succeeds in explaining these disparate movement phenomena within a single framework, strengthening this approach as the foundation for a unified theory of motor control and planning.

Tyrimo objektas: skirtingų kinezioteipo metodikų poveikis blauzdą tiesiančių raumenų jėgos momento variabilumui ir tikslaus judesio atkartojimui tiesiant blauzdą. Tikslas - išsiaiškinti kaip skirtingos kinezioteipavimo metodikos veikia kelio sąnario propriocepciją. Uždaviniai: 1. Ištirti ir palyginti skirtingų kinezioteipavimo metodikų poveikį blauzdą tiesiančių raumenų jėgos momento variabilumui, su ir be vaizdinės grįžtamosios informacijos, kai kelio sąnarys sulenktas 60º kampu. 2. Ištirti ir palyginti skirtingų kinezioteipavimo metodikų poveikį blauzdą tiesiančių raumenų jėgos momento variabilumui, su ir be vaizdinės grįžtamosios informacijos, kai kelio sąnarys sulenktas 90º kampu. 3. Ištirti ir palyginti skirtingų kinezioteipavimo metodikų poveikį tikslaus judesio atkartojimui, tiesiant blauzdą be vaizdinės grįžtamosios informacijos. Hipotezė. Žinant, kad raumeninės kinezioteipavimo metodikos (KT1) naudojimas labiau veikia raumeninius judesio valdymo aspektus, manome, kad judesio variabilumas sumažės ypač prie vidutinio raumens ilgio, o raištinė kinezioteipavimo metodika (KT2) veikianti sąnarinius judesio valdymo aspektus pagerins tikslaus judesio atkartojimą tiesiant blauzdą. Tyrimo metodai ir organizavimas: Tyrimas atliktas Lietuvos kūno kultūros akademijos Judesių klinikinių ir fundamentaliųjų tyrimų centre. Tyrimo pradžioje buvo išmatuoti maksimalūs blauzdą tiesiančių raumenų valingos jėgos momentai, kai koja sulenkta per kelio sąnarį 90° ir 60° kampu. Vėliau buvo... [toliau žr. visą tekstą]
Object of the study: the effect of different kinesio taping techniques for knee isometric torque variability and joint position sense Aim of the study: to investigate the effect of different kinesio taping techniques for knee proprioception Goals of the study: 1. To investigate and compare the effect of different kinesio taping techniques for knee extensors torque variability with and without visual feedback when knee is in 60º flexion. 2. To investigate and compare the effect of different kinesio taping techniques for knee extensors torque variability with and without visual feedback when knee is in 90º flexion. 3. To investigate and compare the effect of different kinesio taping techniques for joint position sense with and without visual feedback. Hypothesis of the study: Knowing that kinesio taping technique for muscle (KT1) affects motor control of muscles, it might be supposed that movement variability will decrease when muscle will be in the medium length and it’s known that kinesio taping technique for ligament (KT2) affects motor control of joints so we believe that it will improve the joint position of the knee. Methods and organization of the study: The study was performed in the Lithuanian Academy of Physical Education in the Center of Movements Clinical and Basic Research. At the beginning maximal isometric knee extension torque at knee joint angles of 60º, 90º was measured. Furthermore, isometric knee extension torque variability at 20% of maximal voluntary... [to full text]

Les maisons individuelles reposant sur une formation argileuse considérée à moyen risque vis-à-vis des phénomènes de réhydratation et dessiccation des sols argileux, ont été particulièrement touchées par les tassements différentiels provoqués par le phénomène depuis les sécheresses de 2003 et 2005 en Gironde (33). Une première partie de la thèse a été de mener une étude sur le comportement gonflant et rétractant de la formation argileuse de Brach d’âge Plio-quaternaire, responsable de centaines de sinistres sur habitations à l’échelle d’un quartier puis à celle de la parcelle, à l’aide des paramètres géotechniques et mécaniques. Elle a mis en évidence l’hétérogénéité des faciès argileux et l’influence des passées sableuses à l’échelle de la formation argileuse. L’autre intérêt de ce travail est la compréhension des mécanismes et des cinétiques d’hydratation et de dessiccation des sols argileux jusqu’à 3 m de profondeur, sur un cycle annuel. L’étude est basée sur une méthode associant les données géophysiques aux valeurs des paramètres géotechniques obtenus in situ et en laboratoire. Ce couplage repose sur une instrumentation géotechnique et géophysique continue sur un site expérimental de la commune de Pessac (Gironde). L’intérêt de cette instrumentation est d’établir des corrélations entre les sollicitations mécaniques enregistrées par le sol (déplacements verticaux) en fonction de l’évolution de la teneur en eau volumique des sols jusqu’à 3 m de profondeur, reliée aux variations de résistivités électriques. Les travaux présentent les premiers résultats comparés entre les données géotechniques et les données géophysiques issues d’un dispositif de tomographie de résistivité électrique installé à demeure, aboutissant à l’obtention de gammes de résistivité électriques variables corrélées aux faciès rencontrés et à la teneur en eau des sols
Homes built on sensitive clayey soils, considered as medium risk, are showing cracks evidencing differential movements occurring in their foundations after drought periods of 2003 and 2005. To address this problem in a first part of the thesis, the swell-shrinkage behaviour has been investigated specifically to the Plio-quaternary clayey formation of Brach, both at the scale of a district and a small land. The results reveal the variability of the clay behaviour when sandy lenses occurred inside the formation. The present work aims to assess geotechnical and compressibility parameters to analyse the variability of the swelling-shrinkage parameters inside a same clayey formation. The aim of a second part of this study is to identify the seasonal soil moisture variations occurring between wet period and dry summer down to 3 meter depth, using a new method integrating geophysical and geotechnical data obtained in situ and in laboratory. This research is based on the setting of an experimental site on Pessac town (Gironde) in order to monitor clayey behavior, to establish correlations between geotechnical properties, water content variations and electrical resistivity on soils over time and every month. The purpose is to survey and evaluate kinetics of soil water content evolution, temperature and vertical displacements down to 3 m depth. This work presents the first results which compare geotechnical, volumetric and electrical resistivity data by combining the field and laboratory measurements

Nous avons expliqué comment le système visuel intègre les informations de mouvement en manipulant la distribution de vitesse locale à l'aide d'une classe bien contrôlée de stimuli de texture aléatoires à large bande appelée Motion Clouds (TM), avec des spectres de fréquence spatio-temporels naturalistes continus. Nos résultats montrent que le gain et la précision des poursuites se détériorent à mesure que la variabilité de la fréquence de stimulation augmente. Dans l'expérience de discrimination de vitesse perceptuelle, nous avons constaté que les MC ayant une largeur de bande légèrement supérieure à la vitesse étaient perçus comme se déplaçant plus rapidement. Cependant, au-delà d'une bande passante critique, la perception d'une vitesse constante a été perdue. Dans une troisième expérience de discrimination, nous avons constaté que pour les contrôleurs multimédias à large bande passante, les participants ne pouvaient plus discriminer la direction du mouvement. Ces résultats suggèrent que lorsqu’on augmente la bande passante de petites à grandes vitesses, l’observateur expérimente différents régimes de perception. Nous avons finalement réalisé une expérience d’échelle de différence de vraisemblance maximale avec nos stimuli MC afin d’étudier ces différents régimes de perception possibles. Nous avons identifié trois régimes dans la plage des valeurs de différence de vitesse testées qui correspondraient à la cohérence de mouvement, à la transparence de mouvement et à l'incohérence complète
It is still not fully understood how the visual system integrates motion information across different spatial and temporal frequencies, in order to build a coherent percept of the global motion under complex, noisy naturalistic conditions. We addressed this question by manipulating local speed distribution (i.e. speed bandwidth Bv) using a well-controlled class of broadband random-texture stimuli called Motion Clouds (MCs), with continuous naturalistic spatiotemporal frequency spectra (Sanz-Leon et al., 2012,; Simoncini et al., 2012).Our results show that pursuit gain and precision deteriorate as stimulus speed variability increases. In the perceptual speed discrimination experiment, we found that MCs with moderately larger speed bandwidth were perceived as moving faster. However, beyond a critical bandwidth (Bv > 0.5 °/s), the perception of a coherent speed was lost. In a third direction discrimination experiment, we found that for large bandwidth MCs participants could no longer discriminate motion direction. These results suggest that when increasing speed bandwidth from a small to a large range, the observer experiences different perceptual regimes. We finally ran a Maximum Likelihood Difference Scaling (Knoblauch & Maloney, 2008) experiment with our MC stimuli to investigate these different possible perceptual regimes. We identified three regimes across the range of tested values of velocity difference, that would correspond to motion coherency (and speed integration), motion transparency and complete incoherency

En todos los deportes de interacción con un móvil, hay alguna acción técnica decisiva para el rendimiento y la victoria. Estas acciones, como el remate en el voleibol, determinante para la victoria en este deporte (Challoumas & Artemiou, 2018; Ureña, 1998), han sido estudiadas con gran interés a lo largo de la historia en condiciones de laboratorio, aisladas del juego real (Oliveira et al., 2020). No obstante, estos abordajes desde la perspectiva de análisis lineal no tienen en cuenta que las oscilaciones del movimiento humano (Couceiro et al., 2014), por lo que realizar un análisis estadístico mediante técnicas lineales nos dará como resultado una información parcial del movimiento (Orellana & Torres, 2010). La aparición de los dispositivos IMU, permitirán afrontar el desafío del análisis no lineal del patrón de movimiento (PM) de la CBR a través del cálculo de su entropía y establecer su relación con la estructura coordinativa del movimiento a través de los cambios en la variabilidad de movimiento (VM) (Preatoni et al., 2013). En esta tesis se aborda el estudio de la CBR como una acción técnica compleja tratándola como un PM mediante tres estudios realizados con 48 jugadoras de diferentes categorías. El primer estudio tuvo como objetivo medir la transmisión de las fuerzas de impacto a la columna vertebral durante la CBR y los tiempos entre fases, para medir las diferencias que se producían entre la CBR con y sin balón. Además, lo analizamos por categorías, lo que nos permitió observar las características del PM de la CBR en cada etapa en cuanto a fuerzas de impacto y tiempos de realización. Las diferencias en ambos, tanto en los momentos de ajuste con el balón como en la duración de la CBR, nos permiten observar cómo la aparición del balón como condicionante externo afecta a la realización de la CBR en el global y en todas las categorías. El segundo estudio tuvo como objetivo analizar de forma no lineal la VM de la CBR realizada por los lados derecho e izquierdo del campo, con y sin balón, como condicionante externo. En conclusión, la VM de la CBR es similar al realizarse por la parte derecha o izquierda del campo, mientras que la VM de la CBR será superior con el condicionante del balón. A su vez, se aprecia una alta VM de la CBR entre las jugadoras, lo que muestra la existencia de un perfil de rendimiento exclusivo, fruto de sus características particulares. El tercer estudio tuvo como objetivo analizar de forma no lineal como afectan los condicionantes internos a la VM de la CBR: Por un lado las diferentes categorías de este deporte (infantil, cadete, juvenil, sénior) y por el otro, los roles específicos del juego (colocadora, punta, central, líbero). La posición punta presentó una menor VM en la CBR respecto a las demás. En el condicionante de la categoría, la VM disminuyó entre las categorías infantil y cadete, estabilizándose en el resto de categorías, tanto con cómo sin balón, mostrando que a partir de la categoría cadete se consolida el PM de la CBR y alcanza su etapa de madurez. En cuanto al condicionante de la posición de juego, sólo afloran diferencias bajo la condición con balón, siendo la posición punta la que tiene valores de VM más bajos, fruto de la mayor práctica de la CBR. El análisis de la VM de un PM a través de la entropía permite identificar cómo la aparición de diferentes condicionantes, internos y externos, modifican los patrones de movimiento El uso individualizado de los IMU en juego real permitirán identificar los PM específicos y analizar su VM.
In this thesis, the spike movement approach (CBR) as the most determining action for the result of volleyball, is studied, as a complex technical action, treating it as a movement pattern (PM). Fourty eight female players of different categories realized three different studies. The first study aimed to measure the transmission of impact forces to the spine during CBR and the times between phases, to measure the differences that occurred between CBR with and without the ball constraint in different categories. They allow us to observe how the appearance of the ball as an external constraint affects the performance of the CBR in global and in all different categories. The second study through a non-linear analysis, calculate the variability of movement (VM) of the CBR performed on the right and left sides of the field, with and without the ball as an external constraint. In conclusion, the VM of the CBR is similar when performed on the right or left side of the field, while the VM of the CBR will be higher with the ball constraint. Otherwise, a high VM of the CBR is appreciated among the players, which shows the existence of an exclusive performance profile, because of their personal characteristics. The third study aimed to analyze the VM of the CBR: the different categories of this sport (infantil, cadete, juvenil, senior) and the specific roles of the game (colocadora, punta, central, libero). The VM decreased between the infantil and cadete categories, stabilizing in the rest of the categories, both with and without the ball, showing that from the cadete category the CBR PM consolidates and reaches its maturity stage. Regarding the determining factor of the playing position, the punta is the one with the lowest VM values, because of the greater practice of the CBR in practices and games. The use of the acceleration signal of a PM to analyze its VM through entropy, has special relevance to be able to identify how the appearance of different internal and external constraints modify movement patterns.

The aim of the study – To determine and assess the variability of movements during the vertical standing jumps with and without the regressive information. Subjects: The subjects were healthy men who cultivate triathlon (age 19-20 years; n = 10). The objectives: to identify and evaluate the variability of vertical jumps when the jumps are performed at 50% of maximal intensity without using the backward information; to identify and evaluate the variability of vertical jumps when the jumps are performed at 50% of maximum with the regressive information about the accuracy of jump; to identify and evaluate the variability of vertical jumps when the jumps are performed at 30% of maximum (before and after the workload) and at maximal intensity (workload) without the use of regressive information; to evaluate the variability of vertical jumps when the jumps are performed at 30% of maximum (before and after the workload) and at maximal intensity (workload) with the backward information for the control jumps. The main conclusions of the study are the following: During the vertical jumps at 50 % of maximum, we have determined similar repetition of vertical jump. This similarity of vertical jumps’ accuracy was determined during the jumps before the workload, during the workload, and after the workload; The repetition of the similar vertical jump depended on the delivery of regressive information: first two jumps with the backward information were significantly increased in comparison to... [to full text]

Tout mouvement humain présente une variabilité inter- et intra-individuelle. Cette variabilité du mouvement (VM) concerne les trajectoires, les coordinations, les forces motrices et les activations musculaires. Pourtant, à ce jour, la VM est quasiment ignorée en conception de postes de travail et il n’existe pas d’outil permettant de la simuler. L’objectif de ces travaux a donc été de développer unhumain virtuel (HV) permettant de simuler les effets d’une source de VM (la fatigue musculaire) sur une tâche de référence (mouvement répétitif de pointage). Un contrôleur d’HV a été développé. Basé sur le modèle de fatigue de Xia et Frey-Law, il implémente des commandes conçues pour simuler certains effets de la fatigue (limitation des efforts, transfert de l’activité motrice, réduction des performances de suivi de trajectoire). L’actionnement de l’HV est calculé par optimisation quadratique à l’aide d’un moteur physiquede simulation dynamique. Des données de mouvement ont été analysées pour identifier la VM induite par la fatigue lors de l’activité de pointage, et valider les commandes d’HV proposées. Une campagne de mesures a été menée en laboratoire. Une analyse en composantes principales (ACP) des données cinématiques a permis d’identifier les degrés de liberté impliqués dans la VM et détecter les transitions d’adaptation du mouvement à la fatigue. Le démonstrateur d’HV restitue certaines caractéristiques de la VM observée.Des améliorations de l’HV sont proposées, mais celui-ci permet déjà de sensibiliser les concepteurs à l’intégration de la VM dans la démarche de prévention dès les premières phases de conception de postes de travail
Every human movement presents an inter- and intra-individual variability. This variability of movement (MV) affects trajectories, coordinations, motor forces as well as muscular activations. However, to date, MV is almost ignored in the workstations design and there is no means to simulate it. The objective of this work was therefore to develop a virtual human (VH) to simulate the effects of one source of VM (muscle fatigue) on a reference task (a repetitive pointing task). A VH controller has been developed. Based on Xia and Frey-Law muscle fatigue model by, it implements controls designed to simulate some effects of muscle fatigue (exertion limitation, transfer of motor activity, reduction of trajectory tracking performance). The actuation of the VH is calculated by quadratic optimization using a dynamic simulation physics engine. Movement data was analyzed to identify fatigue-induced MV during the pointing activity, and to validate the proposed VH controls. An laboratory experiment has been carried out. Principal component analysis (PCA) of kinematic data identified the degrees of freedom involved in the VM and detected transitions of movement patterns with fatigue. This VH demonstrator simulates some characteristics of the MV observed. Improvements of the HV are proposed, however it can already be used to make designers more aware of effects of the VM in occupational risks prevention from the first steps of workstations design

Les troubles musculo-squelettiques (TMS) liés au travail sont des maladies qui interrogent la formation du geste professionnel. Il est admis que ces maladies plurifactorielles nécessitent pour leur prévention des approches interdisciplinaires. Notre action s'inscrit dans le cadre de la théorie historico-culturelle de l'activité (Vygotski, 1978). La recherche en clinique de l'activité organise l'action d'appropriation par les sujets de nouveaux moyens d'agir sur eux-mêmes et sur la situation de travail. Elle débute toujours par une intervention dans un milieu professionnel donné. Nous avons répondu à la demande du service de médecine du travail d'une grande ville française. Des TMS au niveau des épaules et des lombalgies ont été diagnostiqués chez des fossoyeurs municipaux. Nous avons conduit cette intervention en psychologie du travail dans un cadre méthodologique clinique de l'activité ouvert aux coopérations interdisciplinaires avec l'ergonomie de l'activité et l'analyse biomécanique. La co-analyse de gestes techniques au sein de trois collectifs de fossoyeurs a pu bénéficier des apports méthodologiques de l'interdisciplinarité. L'intervention a aussi permis des avancées dans l'action de prévention initiée par les membres de la direction et les préventeurs réunis en comité de pilotage. Au plan conceptuel, le geste est une unité physiologique, psychologique et sociale. Dans l'analyse psychologique et sociale du mouvement (Clot & Fernandez, 2005) cette unité est appréhendée dans la complexité de sa dynamique inter fonctionnelle (Luria, 1973). Le développement du geste est pensé en termes de réorganisation qualitative des rapports internes entre automatisme et geste et entre geste et mouvement (Fernandez, 2004). Cette modélisation est construite sur le modèle des rapports inter fonctionnels entre opération et action et entre action et activité (Léontiev, 1984) ainsi que sur le modèle de l'activité dirigée (Clot, 1999). Ce parcours théorique et nos résultats empiriques font apparaître que les TMS sont des maladies de l'hypo-socialisation du mouvement par défaut d'interférences entre les contextes de sa réalisation. La dynamique des controverses gestuelles entre professionnels et l'organisation d'interférences inter-contextuelles sont analysées comme des méthodes indirectes favorisant la socialisation du mouvement en vue de prévenir les troubles musculo-squelettiques.

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Testes de infiltração com infiltrômetro duplo anel de nível constante foram efetuados em 32 pontos de uma malha retangular de uma parcela agrícola da Fazenda Experimental da EMEPA - Pb. Ajustamentos as Leis de Philip e de Green e Ampt foram efetuados. Medições da granulometria, densidade aparente seca do solo e umidade volumétrica antes e depois dos testes foram também efetuadas. Utilizou-se a seguir técnicas de análises estatística clássica e geoestatística para caracterizar a variabilidade espacial dos parâmetros de infiltração obtidos pelos ajustamentos. Nenhum dos parâmetros estudados apresentou estrutura espacial definida. Correlações simples e múltiplas evidenciaram dependência da percentagem de Argila + Silte com o espaço físico, e independência entro os parâmetros de infiltração. Ilustrações sobre o efeito da variabilidade espacial sobro o ponto de vista agronômico o hidrológico são mostradas.
Infiltration tests with double-ring infiltrometers were performed in a 33 paint reiangular regular]y spaced grid of an agri cultural site. Fitting of the infiltration curve obtained by Philip and Green and Ampt laws allowed to obtain the sorptivity, the infiltration rate at steady state and the suction parameters of Green and Ampt,for each point. Measurements of pre- and post-humidi ty, granulometry and dry density were also performed. Classical statistical and geo-statistical techniques were used to characterize spatial variability. None of the parameters studied showed a defined spatial structure. Single and muitiple correlations showed a dependence between Cclay + siltD percentage with space but no correlation between parameters was obtained. I11ustrative considerations about spatial variability were ma de with agronomic and hydrologic applications.

Although speed-accuracy trade-offs and planning and execution of rapid goaldirected movements have garnered significant research interest, far fewer studies have reported results on the lower end of the movement speed spectrum. Not only do very interesting observations exist that are unique to slow movements, but an explanation of these observations is highly relevant to motor function recovery and motor skill learning, where movements are typically slow at the initiation of therapy or learning, and movement speed increases through practice, exercise or therapy. In the first part of this thesis, based on data from nine stroke patients who underwent a month-long hybrid traditional and robotic therapy protocol, a correlation analysis shows that measures of movement quality based on minimum jerk theory for movement planning correlates significantly and strongly with clinical measures of motor impairment. In contrast, measures of movement speed lack statistical significance and show only weak to moderate correlations with clinical measures. These results constitute an important step towards establishing a much-needed bridge between clinical and robotic rehabilitation research communities. In the second part, the origins of movement intermittency or variability in slow movements are explored. A study with five healthy subjects who completed a manual circular tracking task shows that movement intermittency increases in distal direction along the arm during multi-joint movements. This result suggests that a neuromuscular noise option is favored against a submovement-based central planning alternative, as the source of variability in slow movements. An additional experimental study with eight healthy subjects who completed slow elbow flexion movements at a constant slow speed target under varying resistive torque levels demonstrates that resistive torques can significantly decrease movement speed variability. The relationship between resistive torque levels and speed variability, however, is not monotonic. This finding may constitute a basis for proper design of novel human skill augmentation methods for delicate tasks and improve motor rehabilitation and learning protocols. Finally, a neuro-musculoskeletal model of the elbow suggests that movement speed variability in slow movements cannot be solely attributed to variability in the mechanics of muscle force generation. Together, these analyses, simulations, and experiments shed light on variability in slow movements, and will inform the development of novel paradigms for robotic rehabilitation, motor skill learning and augmentation.

碩士
國立臺東大學
體育學系碩士班
99
Purpose: This study examined the expertise in terms of variability on outcome performance and whole body movement pattern in badminton players. Method: The participated players were ten excellent high school students. They were required to play 10 shots of forehand drop, smash and clear each to an 80cm wide and 80cm long target from a fixed position. The landing location of each strokes and the three dimensions coordinates of the major segments of whole body were recorded. The mean, standard deviation (SD), variable error(VE) were calculated. The principle component analysis (PCA) was implemented on three dimensional coordinates. Results: 1.For consequence of shot. (1)The highest success was clear, the lowest was smash. (2)The drop and smash distribution were tend to center and rear on target. (3)For variable error, individual difference showed in types of shot and repeated shots. 2.For movement coordination. (1)Four components explain 91%-95%. (2) EFFs showed that types of smash was different from others.. No significant difference revealed among components or types. (3)The relative phase on the movement coordination of the selected participant showed temporal difference among vary shots and same shots in particular for the smashes. Conclusions: 1. Although no significant showed among types of shots on the location of landing, the target position vary slightly according to different type. 2. No significant difference showed in movement coordination among types of shots. However, consistent trend of variability of movement coordination were found when the individual players stoke different shots or same shots.

Repetitive stress injuries are common in the workplace where workers perform repetitive tasks continuously throughout the day. Muscle fatigue may lead to injury either directly through muscle damage or indirectly through changes in coordination, development of muscle imbalances, kinematic and muscle activation variability, and/or movement instability. To better understand the role of muscle fatigue in changes in movement parameters, we studied how muscle fatigue and muscle imbalances affected the control of movement timing, variability, and stability during a repetitive upper extremity sawing task. Since muscle fatigue leads to delayed muscle and cognitive response times, we might expect the ability to maintain movement timing would decline with muscle fatigue. We compared timing errors pre- and post-fatigue as subjects performed this repetitive sawing task synchronized with a metronome using standard techniques and a goalequivalent manifold (GEM) approach. No differences in basic performance parameters were found. Significant decreases in the temporal correlations of the timing errors and velocities indicated that subjects made more frequent corrections to their movements post-fatigue. Muscle fatigue may lead to movement instability through a variety of mechanisms including delayed muscle response times and muscle imbalances. To measure movement stability, we must first define a state space that describes the movement. We compared a variety of different state space definitions and found that state spaces composed of angles and velocities with little redundant information provide the most consistent results. We then studied the affect of fatigue on the shoulder flexor muscles and general fatigue of the arm on movement stability. Subjects were able to maintain stability in spite of muscle fatigue, shoulder strength imbalance and decreased muscle cocontraction. Little is known about the time course for adaptations in response to fatigue. We studied the effect of muscle fatigue on movement coordination, kinematic variability and movement stability while subjects performed the same sawing task at two work heights. Increasing the height of the task caused subjects to make more adjustments to their movement patterns in response to muscle fatigue. Subjects also exhibited some increases in kinematic variability at the shoulder but no changes in movement stability. These findings suggest that people alter their kinematic patterns in response to fatigue possibly to maintain stability at the expense of increased variability.
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Movement variability that occurs while performing repetitions of any particular motion can be due to errors in one’s ability to select the required parameters for executing the movement. However, it has been suggested that an optimal amount of variability exists in a healthy system providing adaptability to varying situations while producing negligible errors. Investigation of the consistency of movement variability in a system may provide information regarding joint control and integrity since the functionality of a system can be disrupted by injury. Rupture of the anterior cruciate ligament is associated with deficits in knee joint stability and mobility, as well as altered movement patterns. There is value in developing a simple clinical test that can measure knee joint stability and evaluate the degree of knee damage and rate of progress during rehabilitation. The main objectives were to investigate the normal range of variability during repeated knee extensions in healthy subjects and subjects with a reconstructed anterior cruciate ligament, and to evaluate the reliability of the method. There were 30 participants in the control group and 8 in the subject group. All were physically active a minimum of 2-3 times per week for a total of 2-3 hours. Mean variance and mean correlation were used to evaluate variability in this study. Change in mean variance and mean correlation, standard error of measurement and intra-class correlation coefficient were used to evaluate reliability. The results showed the range of values for movement variability in control and subject groups. Standard error of measurement indicated mean correlation (1.31% to 2.38%) was more reliable than mean variance (21.80% to 54.87%). Mean variance and mean correlation significantly increased with speed, and mean correlation was significantly higher for dominant legs during trials at 70 beats per minute.
Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2014-06-02 12:18:42.802

abstract: The human body is a complex system comprised of many parts that can coordinate in a variety of ways to produce controlled action. This creates a challenge for researchers and clinicians in the treatment of variability in motor control. The current study aims at testing the utility of a nonlinear analysis measure – the Largest Lyapunov exponent (1) – in a whole body movement. Experiment 1 examined this measure, in comparison to traditional linear measure (standard deviation), by having participants perform a sit-to-stand (STS) task on platforms that were either stable or unstable. Results supported the notion that the Lyapunov measure characterized controlled/stable movement across the body more accurately than the traditional standard deviation (SD) measure. Experiment 2 tested this analysis further by presenting participants with an auditory perturbation during performance of the same STS task. Results showed that both the Lyapunov and SD measures failed to detect the perturbation. However, the auditory perturbation may not have been an appropriate perturbation. Limitations of Experiment 2 are discussed, as well as directions for future study.
Dissertation/Thesis
Masters Thesis Psychology 2016

Málková, H.: Multiplication of shape as a means of constructing reality. [Diplom thesis] Prague 2017 - Charles University, Faculty of Education, Department of Art Education, 123 pages. The diploma thesis focuses on the theme of creation of systems, structures and constructions in visual reality. The theoretical part is aimed at the possibilities of multiplication, its growth into space or a plane, while regarding creation of plastic arts by selected artists from the field of fine arts. The practical part introduces author's conception of the topic by the means of photographic medium. Structure is a crucial phenomena in possible understanding of visual reality. It has prerequisites for development of transcendental thinking. We can discover it throughout the whole universe as its unifying element. The findings from the theoretical part are used as basis for didactic activities. The didactic part presents the realized art assignments, which are a part of the implementation of the research. The thesis brings findings and conclusions within the framework of the results of creation and teaching of the topic of spatial composition of multiplied form within a coherent object. KEY WORDS: construction, structure, movement, shape, space, material variability, racionality, photography, object creation,...

To achieve expressive musical results in violin bowing, performers access wide ranges of combined musical tone loudness and duration variables. By comparison, allowable mechanical variability in bow stroke execution may be limited. Such constraints on string bowing variability similarly might limit variability of bowing limb movement. Constrained variability may carry risk of upper extremity musculoskeletal disorders. Therefore if musical and/or bowing-execution variables influence bowing limb movement variability, they may in turn influence risk of cumulative injury in the player. In two experimental studies we examined the influence of the musical variables of duration and sound intensity (loudness) on variability in both string bowing mechanical variables and bowing limb joint moments (i.e. rotational forces) and joint angle trajectories. Five violinists performed playing tasks in which bow strokes varied across four levels of duration and three levels of loudness. Given a constant-amplitude bow stroke, quiet, brief strokes and loud, long strokes had to be executed close to the lower and upper limits of permissible bow-on-string force (bow force). In Study #1, we computed one- and three-dimensional bow movement variance measures, in both kinematic (bow velocity across violin string, distance from bow-to-bridge) and kinetic (bow force) variables. In Study #2 we computed the cycle-to-cycle standard deviation of joint moments and angles for each moment and angular degree of freedom in the bowing limb. In each study, these variability measures were compared across the 12 experimental conditions. We hypothesized that variability would be lowest when executing quiet/brief and loud/long strokes, compared to strokes that could be executed further from bow force limits. However, it was also anticipated that variability instead could be influenced most strongly by bow and/or limb velocity, magnitude of bow force, and/or bowed-string loudness response properties. Results from both studies indicated that variability in both bow-on-string and limb movement was conditioned on these latter properties: tone duration and loudness exerted consistent effects on variances and standard deviations. Contradicting the main hypothesis, variability was not influenced by proximity to bow force limits. We conclude that bowing variability is constrained mainly by factors not specific to variability tolerance at the bow-violin string interface.

The well-known degrees of freedom problem originally introduced by Nikolai Bernstein (1967) results from the high abundance of degrees of freedom in the musculoskeletal system. Such abundance in motor control have two sides: i) because it is unlikely that the Central Nervous System controls each degree of freedom independently, the complexity of the control needs to be reduced, and ii) because there are many options to perform a movement, a repetition of a given movement is never the same. It leads to two main topics in motor control and biomechanics: motor coordination and motor variability. The present thesis aimed to understand how motor systems behave and adapt under specific conditions. This thesis comprises three studies that focused on three topics of major interest in the field of sports sciences and medicine: expertise, injury risk and fatigue. The first study (expertise) has focused on the muscle coordination topic to further investigate the effect of expertise on the muscle synergistic organization, which ultimately may represent the underlying neural strategies. Studies 2 (excessive medial knee displacement) and 3 (fatigue) both aimed to better understand its impact on the dynamic local stability. The main findings of the present thesis suggest: 1) there is a great robustness in muscle synergistic organization between swimmers at different levels of expertise (study 1, chapter II), which ultimately indicate that differences in muscle coordination is mainly explained by peripheral adaptations; 2) injury risk factors such as excessive medial knee displacement (study 2, chapter III) and fatigue (study 3, chapter IV) alter the dynamic local stability of the neuromuscular system towards a more unstable state. This change in dynamic local stability represents a loss of adaptability in the neuromuscular system reducing the flexibility to adapt to a perturbation.
Originalmente introduzido por Nikolai Bernstein (1967), o famoso degrees of freedom problema resulta do abundante número de graus de liberdade presentes no sistema músculo-esquelético. A análise deste tópico tem duas abordagens: i) uma vez que é pouco provável que o Sistema Nervoso Central consiga controlar cada grau de liberdade individualmente, a complexidade do controlo motor tem que ser reduzida, e ii) uma vez que existem várias formas e possibilidades de realizar o mesmo movimento, uma repetição de um gesto nunca é igual a outra. Isto leva a dois pontos de estudo na área do controlo motor e biomecânica: coordenação motora e variabilidade. A presente tese teve como principal objetivo compreender de que forma sistemas de controlo motor se comportam e adaptam em diferentes condições. Esta tese compreende três estudos que abordam três tópicos de grande interesse na área do desporto: expertise, risco de lesão e fadiga. O primeiro estudo (expertise) procurou perceber qual o efeito da expertise na organização sinergista dos músculos (muscle synergy) que parece representar as estratégias neurais de controlo motor. O estudo 2 (desvio medial do joelho) e 3 (fadiga) tiveram como principal objetivo perceber o impacto destas perturbações na estabilidade dinâmica dos sistemas biológicos. Os resultados principais desta tese sugerem: 1) que existe uma grande robustez nos padrões de organização sinergista dos músculos entre nadadores de diferentes níveis (estudo I), indicando que diferenças entre grupos se possa explicar por adaptações periféricas; 2) fatores de risco de lesão como o desvio medial do joelho e a fadiga alteram a estabilidade dinâmica do sistema neuromuscular no sentido de maior instabilidade. Esta alteração representa uma perda de capacidade de adaptação, por parte do sistemas neuromuscular, a eventuais perturbações ao sistema.

碩士
國立臺北護理健康大學
運動保健研究所
105
Background: With the prtice of meditation and meditative movement, our body's production of self-healing power and some studies show that it can increase the parasympathetic, good for fatigue, anxiety and depression. Through the scientific research to know that can offer health benefits of Ryodoraku and heart rate variability for middle-aged and elderly males. Purpos: The study was to explore the effect of Chan-meditation and meditative movement on Ryodoraku and heart rate variability in middle-aged and elderly males. Methods: Participants (age 40-70 years) were at least more than one year experienced in Chan-meditation and meditative movement practice (n=30), control group (CG) was no related experience in practice (n=11). Measured Ryodoraku and heart rate variability were compared to the previous, intervention and post. All the data were analyzed with one-way ANOVA, two-way ANOVA and Scheffé method. The significance level was set at α=.05. Results: In Ryodoraku this part, the average of upper limb bio-energy (pre: 56.08 ± 12.53, post: 59.02 ± 11.41) and Ryodoraku bio-energy (pre: 56.95 ± 11.69, post: 57.97 ± 11.37) in meditative movement group (MM) was bigger than the Chan-meditation group (CM). Average of Ryodoraku bio-energy in CM (pre: 47.44 ± 14.77, post: 42.39 ± 12.85) was decreased and “upper limb and lower limb ratio” (pre: 0.88 ± 0.22, post: 0.91 ± 0.34) was increased after intervention Chan-meditation. All of Ryodoraku values in control group (CG) were decreased significantly (p<.05). The part of heart rate variability values, HF/LF (pre: 2.86 ± 3.96, post: 3.03 ± 3.01)、LF (pre: 492.17 ± 477.62, post: 742.31 ± 761.41) and power (pre: 1533.25 ± 1361.76, post: 2292.35 ± 2485.11) in CM were increased, and except HF/LF (pre: 4.41 ± 4.26, post: 6.4 ± 4.61) the other values in MM were decreased. Conclusion: Some studies show that meditation is able to increase parasympathetic nervous(HF), but in this study found that Chan-meditation can increase the activity of the autonomic nervous system(LF and power), albeit highly similar activity between meditation(relaxation) and Chan-meditation(arousal), but it’s difference of physiological response. Thus, we suggest that appropriately distinguish the various practices from different meditations. In addition, sympathetic and parasympathetic nerves present a staggered pattern in different stages of MM. On the other word, meditative movement can be used to stimulate and regulate the autonomic nervous system. Moreover, the autonomic nervous system was decreased in CG that showed rest for a long time leads to distractibility and depressed.

The most widespread of invasive crayfish in the Czech Republic is the spiny-cheek crayfish (Orconectes limosus). It is a major disease carrier of crayfish plague, caused by the pathogen Aphanomyces astaci. The infection is lethal to European native species of crayfish. Transmission of this disease is usually associated with the spread of crayfish, which is dependent on their movement. The main aim of this work was to evaluate the differences in crayfish migratory activity in the Pšovka brook among seasons, and assess the factors that may affect it, by the use of radiotelemetry and trapping. We tested the hypothesis that crayfish use brook in the period from spring to autumn and then return back into a pond to overwinter. Furthermore, we evaluated how far from the pond crayfish migrate, and whether there is any relationship between migration and the season or water temperature. The results demonstrate that the activity varies among seasons (being strongly affected by breeding season) but in most studied periods did not significantly depend on water temperature. According to our monitoring, the spiny-cheek crayfish does not spread substantially to upstream parts of the Pšovka. Seasonal migration between the pond and the brook was monitored using two-way flow-through traps installed at the mouth of...

Trial-to-trial variability in human movement is often overlooked and averaged out, but useful information can be gleaned on the brain’s control of variability. A task can be defined by a function specifying a solution manifold along which all task variable combinations will lead to goal success – the Goal-Equivalent Manifold (GEM). We selected a reaching task with variables reach Distance (D) and reach Time (T). Two GEMs were selected: a constant D/T and constant D×T. Subjects had no knowledge of the goal prior to the experiments and were instructed only to minimize error. Subjects learned the generalized tasks by reducing errors and consolidated learning from one day to the next, generalized learning from the D×T to the D/T GEM, and had interference of learning from the D/T to the D×T GEM. Variability was structured along each GEM significantly more than perpendicular to it. Deviations resulting in errors were corrected significantly more quickly than any other deviation. Our results indicate that subjects can learn generalized reaching tasks, and the brain exploits redundancy in those tasks.
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碩士
國防醫學院
護理研究所
103
Background: Hypertension, one of the leading causes of death around the world, is a continuously increasing global health problem. The patients with hypertension often unconsciously recognize their disease conditions, and delay to receive the treatment. Due to the chronic disease situation and the difficulty to control the blood pressure, hypertension patients often experience emotional distress, such as anxiety and depression, which may affect blood pressure control and heart rate variability. There is no study to examine the effect of eye movement desensitization and reprocessing （EMDR）on improving psychological emotional distress and blood pressure control in patients with hypertension. Purpose: The study aimed to examine the effect of EMDR intervention on improving anxiety, depression, illness representation, quality of life, blood pressure and heart rate variability in patients with hypertension. Method: This is an experimental longitudinal design study, which was conducted in a medical center. Total of 102 patients were randomly assigned into experimental group (n = 50) and control group (n = 52). Patients in the experimental group received four-week EMDR intervention, and in control group received general nursing care. Data were collected for four times: pretest, posttest, one-month follow-up, and three-month follow-up. The instruments included the Hospital Anxiety and Depression Scale-Anxiety Subscale, Epidemiology Center Depression Inventory, Brief Illness Representation Scale, World Health Organization Quality of Life Scale, sphygmomanometer, and Check My Heart V 3.0 handheld HRV apparatus. Data were analyzed by using generalized estimating equation （GEE）. Results: Compared to the patients in the control group at posttest, one-month follow-up, and three-month follow-up, the patients in experimental group have a significant reduce on the scores of Hospital Anxiety and Depression Scale-Anxiety Subscale（p < 0.001）；a significant reduce on the scores of Epidemiology Center Depression Inventory（p < 0.001）；a significant reduce on the scores of Brief Illness Representation Scale（p < 0.001）；a significant reduce on the level of systolic blood pressure（p <0.001）；a significant reduce of LF norm （p < 0.001）；a significant improve of HF norm（p < 0.001）；and a significant reduce of LF/HF ratio（p < 0.001）. However, there is no significant difference between groups on the changes of the scores of World Health Organization Quality of Life Scale, and the level of diastolic blood pressure. Conclusion: Eye Movement Desensitization and Reprocessing intervention may improve anxiety, depression, negative illness representation, systolic blood pressure and heart rate variability in patients with hypertension.

碩士
國立陽明大學
物理治療暨輔助科技學系
102
Background and purposes: Preterm infants are at risk for motor impairments related to movement variability. We aimed to investigate the relationship between the variability of stepping movements and the age of walking attainment in infants, and to compare the differences of variability of stepping movements between preterm and full-term infants. Methods: Twenty-seven preterm and 19 full-term infants (GA=29±4 vs. 39±1 weeks; BW=1.2±0.6 vs. 3.4±0.5 kg) were examined for supported stepping on a treadmill (0.2 m/s) at 7 and 9 months and age of walking attainment (independent walking ≧5 consecutive steps). Three dimensional stepping movements were collected using 2 synchronized 60-Hz video cameras and were analyzed using the Peak Performance Motion Analysis System. Variability of stepping movements was indexed using approximate entropy (ApEn), modified multiscale entropy (MMSE), and standard deviation (SD). The associations between ApEn, MMSE, and SD of step variables and walking outcome were examined using linear regression analysis and Cox's proportional-hazards regression analysis. The differences of ApEn, MMSE, SD of step variables, and AIMS scores between preterm and full-term infants and across time, and the change of stepping variability from the second last trial to the last trial were examined using repeated measure Analysis of Variance (ANOVA). Results: Regression analysis exhibited that a higher 9-months ApEn of ankle angle, a higher 7-months SD of knee angle, a higher 9-months SD of knee velocity, and a higher 9-months SD of ankle velocity were significantly associated with an older age of walking attainment when adjusted for prematurity. A significant time*group interaction effect for the ApEn of hip angle, the MMSE of knee velocity and acceleration, hip acceleration, and the SD of ankle acceleration, a significant time effect for the ApEn of knee angle, and a significant group effect for the ApEn of knee velocity, the SD of hip angle, ankle angle, and ankle velocity for were found. Compare to the second last trial, a higher ApEn of ankle angle and acceleration, and knee velocity, a higher MMSE of knee velocity and acceleration, and ankle acceleration, and a lower SD of all the hip variables at the last test trial than the second last test trial, a higher SD of all the knee and ankle step variables were found at the last test trial. Discussion: Increased irregularity in the motor behavior might reflect the reduction in the adaptability of a system which lead to late achievement of independent walking. Results of MMSE without prediction and group differences might be caused from the inappropriate algorithm for the data in this study. Both linear and nonlinear measurements had prediction for age of walking attainment indicated that they could provide different aspect for movement variability during supported treadmill stepping in infants. In conclusion, there were differences of stepping variability between preterm and full-term infants and prediction of stepping variability for age of walking attainment. ApEn was a more appropriate measurement than MMSE for the variability of stepping movement patterns in this study. In addition, we found the variability of hip movement control increased as the independent walking accomplished, yet variability of knee and ankle movement control decreased.