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1
Zagrevskiy, V., and O. Zagrevskiy. "SYNTHESIS OF PROGRAM AND FINITE LAWS OF MOTION IN ANALYTICAL MODELS OF CONTROL OF THE FINAL STATE OF BIOMECHANICAL SYSTEMS." Human Sport Medicine 19, no. 1 (May 27, 2019): 93–99. http://dx.doi.org/10.14529/hsm190113.
Повний текст джерелаАнотація:
Aim. The article deals with developing a computer program to simulate the movement of the object with a given initial and final speed and fixed travel time. Materials and methods. The analysis, as a method of biomechanics, allows us to assess the biomechanical state of the athlete in real sports exercises. The function of motion synthesis is the ability to predict the trajectory and behavior of the biomechanical system at specified reference points of the phase structure of the simulated motion. The article deals with one of the methods of biomechanical synthesis of movements: synthesis of control of the final state of biomechanical systems, based on the reduction of finite control to a given program control after attenuation of the transient component of acceleration. The mathematical description of the object motion is based on the known law of finite control with feedback. Integration of the mathematical model constructed in the form of the differential equation of the second order was carried out by one of the numerical methods of integration: Runge–Kutta method of the fourth order of accuracy. Consideration of the method is based on a mathematical apparatus describing the motion of a material point, which can be represented by a common center of mass of a biomechanical system, a joint, a center of mass of a segment, etc. Results. The mathematical model of the motion of a material point with the given kinematic parameters of motion at the initial and final moments is implemented in a computer program in the Visual Basic 2010 language environment based on the integrated development environment Visual Studio Express 2013. The output provides numerical and visual support for simulation results. Conclusion. It is shown that the developed computer model of the method always implements the goal of motion: to transfer an object from a given initial state by speed to a given final state for a fixed time of movement.
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Kozin, S. V. "Biomechanical substantiation of the technique of hanging in rock climbing." Health, sport, rehabilitation 5, no. 1 (March 30, 2019): 25. http://dx.doi.org/10.34142/hsr.2019.05.01.03.
Повний текст джерелаАнотація:
<p><em>The purpose</em> of the work is to identify the main kinematic characteristics of a hanging in rock climbing by athletes of different qualifications and theoretically substantiate the correct technique for performing of a given movement. <em>Material and methods.</em> The technique of hanging performance in bouldering of 20 leading climbers of the World and Ukraine and 20 beginner male amateur climbers was analyzed. The age of athletes was 22.4 ± 3.2 years, body length 178.5 ± 12.5 cm, body weight 72.2 ± 8.5 kg. A qualified athlete took part in a demonstration of various models for performing a hang. Using the Kinovea 0.8.15 computer program, the kinematic characteristics of the two models of technology were analyzed (model 1 — typical for novice athletes, model 2 — typical of qualified athletes) based on determining the angle between the shoulder and shoulder girdle, as well as between the lumbar spine and vertical axis. Results. The main kinematic parameters of vibration in climbing for various models of equipment, characteristic of athletes of different qualifications, are revealed. The presence of significant differences (p <0.001) in the angles between the shoulder and the upper arm, between the lower spine and the vertical axis in the fixation phase of the vis is shown. The angle between the shoulder and shoulder girdle in the first model of technology was 1460, in the second model of technology this angle is 970. The angle between the lumbar spine and the vertical axis was 110 in the first model, in the second model this angle was 280. A theoretical justification of the correct hanging technique climbing in terms of the laws of mechanics and the laws of the interaction of forces in the kinematic chain. Findings. In the first model, vis is carried out mainly due to the ligamentous apparatus of the joints of the shoulder girdle with minimal inclusion of muscles, which is dangerous by injury to the ligaments of the shoulder joint. In the second model, VIS also provides for the inclusion of the muscles of the trunk and legs, which reduces the load on the ligamentous apparatus and reduces the chance of injury to the ligaments of the shoulder joint.</p>
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Canton, Stephen P., Tom Gale, Dukens LaBaze, William Anderst, and MaCalus V. Hogan. "An In Vivo Biomechanical Analysis of Syndesmotic Surgical Repair in Elite Athletes: Screw versus Suture Button Fixation." Foot & Ankle Orthopaedics 5, no. 4 (October 1, 2020): 2473011420S0015. http://dx.doi.org/10.1177/2473011420s00152.
Повний текст джерелаАнотація:
Category: Trauma; Basic Sciences/Biologics Introduction/Purpose: Syndesmotic injuries account for 1-11% of all ankle sprains and are the most predictive factor of chronic ankle dysfunction 6 months after injury. Common surgical techniques include screw fixation (the ‘gold standard’) and dynamic fixation with a suture button device, which may lead to better clinical outcomes than rigid screw. To date, there are no studies comparing the in vivo biomechanics of suture button and rigid screw syndesmotic fixation, and no report of the correlations between biomechanics and patient outcomes. The goal of this study is to characterize the biomechanics of the native ankle syndesmosis, rigid screw fixation, suture button fixation, along with associated patient-reported outcomes. This study will elucidate mechanisms for improved patient-reported outcomes based on the fixation method. Methods: 6 patients (average age:23.6, 4M/1F, 2 suture button, 2 screw fixation and 1 hybrid) consented to participate in this IRB-approved study. After being medically cleared to return to full athletic participation, each participant performed seven movements (two single leg hops (straight and lateral), two alternating single-leg push-offs (front-to-back and side-to-side), vertical jumping, running, and walking within a biplane radiographic system (Figure 1). A validated volumetric model-based tracking system matched patient-specific 3D bone models (obtained from CT) to the synchronized biplane radiographs (Figure 1). Six degree of freedom ankle kinematics were determined for each movement and for the repaired and contralateral ankle of each participant. Patient reported outcomes were also measured using the Foot and Ankle Ability Measure (FAAM) and a Visual Analogue Scale (VAS). Results: The results show that the screw fixation (-0.99 mm) has greater tibiotalar lateral-medial translation of the injured side relative contralateral healthy side compared to the tightrope fixation (-0.73 mm) and hybrid (.05 mm). For the syndesmosis translation, the screw fixation (2.00 mm) also exhibits greater total magnitude of translation compared to the tightrope ((-0.44 mm) and hybrid fixation (1.02 mm). Conclusion: This study shows that the screw fixation exhibits greater translation of the syndemosis and lateral/medial translation of the Talus. This may suggest that this method is inferior to the tight-rope and hybrtid. Future studies will include all the motions and more subjects.
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VandenBerg, Curtis D., Mia J. Katzel, Veronica Beltran, Adriana S. Conrad-Forrest, and Tishya A. L. Wren. "EFFECT OF AUTOGRAFT TYPE ON RECOVERY OF KNEE EXTENSOR MECHANISM FUNCTION FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION." Orthopaedic Journal of Sports Medicine 9, no. 7_suppl3 (July 1, 2021): 2325967121S0009. http://dx.doi.org/10.1177/2325967121s00094.
Повний текст джерелаАнотація:
Background: While multiple studies have shown clear benefits of autograft over allograft for anterior cruciate ligament reconstruction (ACLR) in young athletes, disagreement remains regarding the optimal autograft choice. Recovery from ACLR may be influenced by autograft type, which can include iliotibial band (IT), hamstring tendon (HT), quadriceps tendon (QT), or patellar tendon (PT) depending on skeletal maturity and surgeon preference. Hypothesis/Purpose: This study compared knee joint function among pediatric athletes with different types of ACLR autografts. We hypothesized that knee extensor function would recover faster for graft types that did not disrupt the knee extensor mechanism (i.e., IT and HT vs. PT and QT). Methods: This retrospective study examined 138 pediatric athletes (73 female; mean age 15.5, SD 2.2, range 8-21 years) who had undergone sports biomechanical testing in our motion analysis laboratory following recent unilateral ACLR (mean 7.7, range 3-18 months post-surgery). All reconstructions used autografts including 20 IT, 26 HT, 37 QT, and 55 PT. Lower extremity sagittal plane kinematics and kinetics were measured during vertical drop jump landing (41 cm height) and 45° cutting. Maximum knee flexion angles, internal knee extensor moments, and energy absorption during the landing phase (initial contact to peak knee flexion) of each movement were compared among graft types and sides (ACLR vs. contralateral) using linear mixed models with sex, age, and time since surgery as covariates. Results: Knee flexion was significantly lower on the operated vs. contralateral side for HT, QT, and PT during drop jump and for QT and PT during cutting (p<0.001). All graft types exhibited lower knee extensor moments and energy absorption on the operated side (p<0.05). This asymmetry was most pronounced for QT and PT and least pronounced for IT (Figure 1.1). Loading on the operated limb decreased from IT to HT to QT and PT, while loading on the contralateral limb increased similarly. Asymmetry of kinetics was significantly lower for IT compared with both QT and PT during both movements (p<0.01). Similar patterns were observed for HT but were not always statistically significant. No differences in asymmetry were observed between IT and HT or between QT and PT. Conclusion: Young athletes with IT and HT autografts exhibit greater engagement of the knee extensors during dynamic loading than peers with PT or QT autografts in the 18 months following ACLR. This may be due to extensor mechanism donor site morbidity associated with PT and QT grafts. Tables/Figures: [Figure: see text]
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Al-Lami, Wael Abdullah Hussein, and G. B. Severukhin. "MAIN DIRECTIONS OF BIOMECHANICAL CHARACTERISTICS Of JAVELIN THROW." Bulletin of Udmurt University. Series Philosophy. Psychology. Pedagogy 29, no. 4 (December 25, 2019): 471–77. http://dx.doi.org/10.35634/2412-9550-2019-29-4-471-477.
Повний текст джерелаАнотація:
At present, the effectiveness of training an athlete should be based not only on the experience and methodological skills of a trainer, but also on the ability to use modern technical tools, equipment that allows to receive urgent information about the various components of the training process in javelin throwing this should be based on equipment allowing to obtain biochemical analysis data. The article shows the possibilities of using biomechanical models in the training of athletes. Approaches to the construction of biomechanical models are considered. A biomechanical model of javelin throwing has been developed. The solution of the dynamics problem is given: the range of the spear’s flight depends on the absolute initial departure speed, departure angle, and spear release height. The most significant biomechanical characteristics of the “athlete-spear” system are determined. The possibilities of using the individual characteristics of an athlete in achieving the best results are shown.
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McGhie, David, and Gertjan Ettema. "Biomechanical Analysis of Surface-Athlete Impacts on Third-Generation Artificial Turf." American Journal of Sports Medicine 41, no. 1 (November 13, 2012): 177–85. http://dx.doi.org/10.1177/0363546512464697.
Повний текст джерелаАнотація:
Background: Excessive repetitive loads are widely believed to be the cause of overload or overuse injuries. On third-generation artificial turf, impacts have been found to vary with surface and shoe properties. Mechanical devices are considered not representative for measuring impact absorption during athletic movements, and pressure insoles have been shown as inaccurate with regard to magnitude of force. Purpose: To compare impact properties between different third-generation artificial turf systems in combination with various cleat configurations in vivo using force plate technology. Study Design: Controlled laboratory study. Methods: Twenty-two male soccer players (mean ± SD: age, 23.1 ± 2.8 y; height, 1.81 ± 0.1 m; body mass, 77.5 ± 6.0 kg) performed 10 short sprints, 5 straight with a sudden stop and 5 with a 90° cut, over a force plate covered with artificial turf for each combination of 3 turf systems and 3 cleat configurations. Results: During stop sprints, peak impact was significantly higher on a recreational-level turf system than professional-level turf systems with and without an underlying shock pad (3.12 body weight [ W] vs 3.01 W and 3.02 W, respectively). During cut sprints, peak impact was significantly higher with traditional round cleats than with turf cleats and bladed cleats (2.99 W vs 2.84 W and 2.87 W, respectively). Conclusion: The results indicate that both an increase in assumed impact-absorbing surface properties and a larger distribution of shorter cleats produced lower impacts during standardized athletic movements. Regardless, none of the shoe-surface combinations yielded peak impacts of an assumed hazardous magnitude. Clinical Relevance: The study provides information on the extent to which various third-generation artificial turf systems and cleat configurations affect impact force, widely believed to be a causative factor for overload and overuse injuries.
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Petrovic, Milos, Haraldur B. Sigurðsson, Hjálmar J. Sigurðsson, Thorarinn Sveinsson, and Kristín Briem. "Effect of Sex on Anterior Cruciate Ligament Injury–Related Biomechanics During the Cutting Maneuver in Preadolescent Athletes." Orthopaedic Journal of Sports Medicine 8, no. 7 (July 1, 2020): 232596712093698. http://dx.doi.org/10.1177/2325967120936980.
Повний текст джерелаАнотація:
Background: There are 2 movement patterns associated with an anterior cruciate ligament (ACL) injury: dynamic valgus and stiff landing. Although sex-dependent differences have been identified for adults, less is known for preadolescent athletes regarding movement patterns known to load the ACL. Hypothesis: We hypothesized that girls would demonstrate greater vertical ground reaction forces and knee valgus angles. We further hypothesized that the exercise intervention would affect girls more than boys and that this would primarily be demonstrated in less sagittal plane excursions, increased vertical ground reaction forces and knee valgus moments for girls than for boys. Study Design: Controlled laboratory study. Methods: Male and female soccer and handball players (n = 288; age range, 9-12 years) were recruited. A motion capture system synchronized to a force platform was used to record 5 trials of a cutting maneuver before and after a 5-minute fatigue intervention. Linear mixed models were constructed, and analysis of variance was used to analyze differences in outcomes associated with the sex of the athletes. Results: Boys showed greater peak knee valgus moment (0.26 vs 0.22 N·m/kg, respectively; P = .048), peak knee internal rotation moment (–0.13 vs –0.10 N·m/kg, respectively; P = .021), knee rotation excursion (–7.9° vs –6.9°, respectively; P = .014), and knee extension excursion (2.7° vs 1.4°, respectively; P < .001) compared with that in girls. A significant sex × fatigue intervention interaction ( F = 7.6; P = .006) was found, which was caused by a greater increase in first peak vertical ground-reaction force (vGRF) from before to after the fatigue intervention for girls (15.3 to 16.0 N/kg) compared with boys (16.4 to 16.5 N/kg). Conclusion: Differences detected for biomechanical factors during the cutting maneuver do not point to a greater ACL injury risk for prepubescent or early pubescent girls than for boys. Nonetheless, girls go on to develop more detrimental movement patterns in adolescence than those in boys in terms of biomechanical risk factors. Clinical Relevance: Early adolescence is a good target age to learn and develop muscular control; balance, strength; flexibility; and jumping, running, and landing control. This time of physical and athletic growth may therefore be an appropriate period to influence biomechanical factors and thereby task execution and the injury risk.
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Zhang, Chuan Bo. "Biomechanical Analysis of Starting Action on an Outstanding Short Track Speed Skating Female Athlete." Applied Mechanics and Materials 459 (October 2013): 530–34. http://dx.doi.org/10.4028/www.scientific.net/amm.459.530.
Повний текст джерелаАнотація:
The first three steps of staring action of a superb female athlete, who is in the Short track speed skating teamin Jilin province, were analyzed by Simi motion-Biomechanical Analysis System. Through an Analysis of Parameter by the Theory of Sports Biomechanics, we know the spending time and length of each step of the first three steps. After we compare our local Short Track Speed Skaters with those who are famous in china and the whole world, in the field of Technical characteristics and technical movements of start action, we find that for our local athletes, their consumed time of the first step among the first three steps is more than that spent by excellent Short Track Speed Skating female athletes in Our country and the world, but as for the length, theirs are shorter.
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Cos, Ignasi, Nicolas Bélanger, and Paul Cisek. "The influence of predicted arm biomechanics on decision making." Journal of Neurophysiology 105, no. 6 (June 2011): 3022–33. http://dx.doi.org/10.1152/jn.00975.2010.
Повний текст джерелаАнотація:
There is considerable debate on the extent to which biomechanical properties of movements are taken into account before and during voluntary movements. For example, while several models have described reach planning as primarily kinematic, some studies have suggested that implicit knowledge about biomechanics may also exert some influence on the planning of reaching movements. Here, we investigated whether decisions about reaching movements are influenced by biomechanical factors and whether these factors are taken into account before movement onset. To this end, we designed an experimental paradigm in which humans made free choices between two potential reaching movements where the options varied in path distance as well as biomechanical factors related to movement energy and stability. Our results suggest that the biomechanical properties of potential actions strongly influence the selection between them. In particular, in our task, subjects preferred movements whose final trajectory was better aligned with the major axis of the arm's mobility ellipse, even when the launching properties were very similar. This reveals that the nervous system can predict biomechanical properties of potential actions before movement onset and that these predictions, in addition to purely abstract criteria, may influence the decision-making process.
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Litvinenko, Y. V., Tomasz Niznikowski, and V. N. Boloban. "Evaluation of the kinematic structure of indicators key elements of sports equipment exercise by postural orientation movements." Physical education of students 18, no. 6 (December 28, 2014): 29–36. http://dx.doi.org/10.15561/20755279.2014.0606.
Повний текст джерелаАнотація:
Purpose : Examine the kinematic structure of indicators key elements of sports equipment exercise (difficult to coordinate). The method of postural orientation movements. Material : The study involved acrobats jumpers on the path of high qualification (n = 7). The method used video - computer recording the movements of the athlete. Results : Identified nodal elements of sports equipment double back somersault tuck. Exercise performed after rondat and double back flip and stretch after rondat - flick (coup ago). In the preparatory phase of motor actions acrobatic exercises isolated and studied central element of sports equipment - starting posture of the body; in the phase of the main motor action - animation poses of the body; in the final phase - the final body posture (stable landing). Conclusions : The method of video - computer registration allowed to perform a biomechanical analysis and evaluation of key elements of sports equipment double back somersault tuck and a double back flip and stretch. Also gain new knowledge about the mechanism of the phase structure of movements when performing double somersaults.
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RIENER, ROBERT, THOMAS FUHR, and JOHANNES SCHNEIDER. "ON THE COMPLEXITY OF BIOMECHANICAL MODELS USED FOR NEUROPROSTHESES DEVELOPMENT." Journal of Mechanics in Medicine and Biology 02, no. 03n04 (September 2002): 389–404. http://dx.doi.org/10.1142/s0219519402000459.
Повний текст джерелаАнотація:
The use of mathematical models has the potential to enhance the development of lower extremity neuroprostheses (NP) based on Functional Electrical Simulation (FES). The choice of model complexity is not trivial when building a model for FES control design. On the one hand, a comprehensive model might be useful to account for the many different biomechanical and neurophysiological effects that can be observed during FES-induced movements. On the other hand, too complex models are difficult to be utilized in and identified for NP applications. In this paper we discuss the disadvantages of too complex models, and propose potential simplifications on the basis of existing models that are commonly used to describe muscle activation, muscle contraction and body-segmental motion. The obtained model approach is simple enough to be identified, and sufficiently comprehensive to describe most of the relevant effects that occur during FES-induced locomotion.
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Demp, PH. "Geometric models that classify structural variations of the foot." Journal of the American Podiatric Medical Association 88, no. 9 (September 1, 1998): 437–41. http://dx.doi.org/10.7547/87507315-88-9-437.
Повний текст джерелаАнотація:
The author presents a description of three geometric models to serve as a framework for establishing a numerical classification system of unlimited refinement for structural variations of the foot and foot types. Such a classification system may identify different forms (foot types) that may be closely aligned to complex movements of the foot (dynamic foot function). This may help in the diagnosis and treatment of biomechanical disabilities. Clinical evaluations are based on radiographic landmark data from weightbearing radiographs.
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Zeng, Ming, Chang Wei Chen, Qing Hao Meng, Hong Lin Ren, and Shu Gen Ma. "Biomechanical Analysis of Typical Upper Limb Movements Based on Kinect-LifeMOD." Applied Mechanics and Materials 599-601 (August 2014): 534–38. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.534.
Повний текст джерелаАнотація:
In traditional biomechanical analysis of upper limb, the high-precision motion data and lifelike human models are needed. It is obvious that those processes are costly and time-consuming. In this paper, a novel and simple combination method based on Kinect-LifeMOD is proposed. Firstly, the Microsoft Kinect (a latest depth sensor) is used to build a cheap and precise motion capture platform. Real-time and reliable key-node rotation data of human skeletons can be acquired by this motion capture system. Next, rotation data is converted into position data as the input of the LifeMOD software which can establish mathematical model of upper limb and execute biomechanical analysis automatically. The experimental results show that the proposed method could achieve the satisfactory performance.
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Örücü, Serkan, and Murat Selek. "Design and Validation of Rule-Based Expert System by Using Kinect V2 for Real-Time Athlete Support." Applied Sciences 10, no. 2 (January 15, 2020): 611. http://dx.doi.org/10.3390/app10020611.
Повний текст джерелаАнотація:
In sports and rehabilitation processes where isotonic movements such as bodybuilding are performed, it is vital for individuals to be able to correct the wrong movements instantly by monitoring the trainings simultaneously, and to be able to train healthily and away from the risks of injury. For this purpose, we designed a new real-time athlete support system using Kinect V2 and Expert System. Lateral raise (LR) and dumbbell shoulder press (DSP) movements were selected as examples to be modeled in the system. Kinect V2 was used to obtain angle and distance changes in the shoulder, elbow, wrist, hip, knee, and ankle during movements in these movement models designed. For the rule base of Expert System developed according to these models, a 28-state rule table was designed, and 12 main rules were determined that could be used for both actions. In the sample trainings, it was observed that the decisions made by the system had 89% accuracy in DSP training and 82% accuracy in LR training. In addition, the developed system has been tested by 10 participants (25.8 ± 5.47 years; 74.69 ± 14.81 kg; 173.5 ± 9.52 cm) in DSP and LR training for four weeks. At the end of this period and according to the results of paired t-test analysis (p < 0.05) starting from the first week, it was observed that the participants trained more accurately and that they enhanced their motions by 58.08 ± 11.32% in LR training and 54.84 ± 12.72% in DSP training.
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de-Oliveira, Levy Anthony, Juan Ramón Heredia-Elvar, José Luis Maté-Muñoz, Juan Manuel García-Manso, José Carlos Aragão-Santos, and Marzo Edir Da Silva-Grigoletto. "Analysis of Pacing Strategies in AMRAP, EMOM, and FOR TIME Training Models during “Cross” Modalities." Sports 9, no. 11 (October 20, 2021): 144. http://dx.doi.org/10.3390/sports9110144.
Повний текст джерелаАнотація:
Empirically, it is widely discussed in “Cross” modalities that the pacing strategy developed by an athlete or trainee has a significant impact on the endurance performance in a WOD in the AMRAP, EMOM, or FOR TIME model. We can observe at least six pacing strategies adopted during the cyclical modalities in the endurance performance in the scientific literature. However, besides these modalities, exercises of acyclical modalities of weightlifting and gymnastics are performed in the “Cross” modalities. These exercises may not allow the same pacing strategies adopted during cyclic modalities’ movements due to their motor characteristics and different intensity and level of effort imposed to perform the motor gesture. In addition to the intensity and level of effort that are generally unknown to the coach and athlete of the “Cross” modalities, another factor that can influence the adoption of a pacing strategy during a WOD in the AMRAP, EMOM, or FOR TIME model is the task endpoint knowledge, which varies according to the training model used. Thus, our objective was to evaluate situations in which these factors can influence the pacing strategies adopted in a self-regulated task with cyclic and acyclic modalities movements during an endurance workout in the AMRAP, EMOM, and FOR TIME model. Given the scarcity of studies in the scientific literature and the increasing discussion of this topic within the “Cross” modalities, this manuscript can help scientists and coaches better orient their research problems or training programs and analyze and interpret new findings more accurately.
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Cohen, Raymond C. Z., Paul W. Cleary, Simon M. Harrison, Bruce R. Mason, and David L. Pease. "Pitching Effects of Buoyancy During Four Competitive Swimming Strokes." Journal of Applied Biomechanics 30, no. 5 (October 2014): 609–18. http://dx.doi.org/10.1123/jab.2013-0260.
Повний текст джерелаАнотація:
The purpose of this study was to determine the pitching effects of buoyancy during all competitive swimming strokes—freestyle, backstroke, butterfly, and breaststroke. Laser body scans of national-level athletes and synchronized multiangle swimming footage were used in a novel markerless motion capture process to produce three-dimensional biomechanical models of the swimming athletes. The deforming surface meshes were then used to calculate swimmer center-of-mass (CoM) positions, center-of-buoyancy (CoB) positions, pitch buoyancy torques, and sagittal plane moments of inertia (MoI) throughout each stroke cycle. In all cases the mean buoyancy torque tended to raise the legs and lower the head; however, during part of the butterfly stroke the instantaneous buoyancy torque had the opposite effect. The swimming strokes that use opposing arm and leg strokes (freestyle and backstroke) had smaller variations in CoM positions, CoB positions, and buoyancy torques. Strokes with synchronized left-right arm and leg movement (butterfly and breaststroke) had larger variations in buoyancy torques, which impacts the swimmer’s ability to maintain a horizontal body pitch for these strokes. The methodology outlined in this paper enables the rotational effects of buoyancy to be better understood by swimmers, allowing better control of streamlined horizontal body positioning during swimming to improve performance.
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Birdwell, J. Alexander, Joseph H. Solomon, Montakan Thajchayapong, Michael A. Taylor, Matthew Cheely, R. Blythe Towal, Jorg Conradt, and Mitra J. Z. Hartmann. "Biomechanical Models for Radial Distance Determination by the Rat Vibrissal System." Journal of Neurophysiology 98, no. 4 (October 2007): 2439–55. http://dx.doi.org/10.1152/jn.00707.2006.
Повний текст джерелаАнотація:
Rats use active, rhythmic movements of their whiskers to acquire tactile information about three-dimensional object features. There are no receptors along the length of the whisker; therefore all tactile information must be mechanically transduced back to receptors at the whisker base. This raises the question: how might the rat determine the radial contact position of an object along the whisker? We developed two complementary biomechanical models that show that the rat could determine radial object distance by monitoring the rate of change of moment (or equivalently, the rate of change of curvature) at the whisker base. The first model is used to explore the effects of taper and inherent whisker curvature on whisker deformation and used to predict the shapes of real rat whiskers during deflections at different radial distances. Predicted shapes closely matched experimental measurements. The second model describes the relationship between radial object distance and the rate of change of moment at the base of a tapered, inherently curved whisker. Together, these models can account for recent recordings showing that some trigeminal ganglion (Vg) neurons encode closer radial distances with increased firing rates. The models also suggest that four and only four physical variables at the whisker base—angular position, angular velocity, moment, and rate of change of moment—are needed to describe the dynamic state of a whisker. We interpret these results in the context of our evolving hypothesis that neural responses in Vg can be represented using a state-encoding scheme that includes combinations of these four variables.
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JHOU, SHU-YU, KAO-SHANG SHIH, PO-SHENG HUANG, FANG-YU LIN, and CHING-CHI HSU. "BIOMECHANICAL ANALYSIS OF DIFFERENT SURGICAL STRATEGIES FOR THE TREATMENT OF ROTATIONALLY UNSTABLE PELVIC FRACTURE USING FINITE ELEMENT METHOD." Journal of Mechanics in Medicine and Biology 19, no. 02 (March 2019): 1940015. http://dx.doi.org/10.1142/s0219519419400153.
Повний текст джерелаАнотація:
A rotationally unstable pelvic fracture can lead to loss of function and limit moving ability. Immediate fracture fixation is needed for patients with the pelvic fractures. However, it may be difficult to evaluate different surgical strategies for the fracture treatments due to variations in patients’ anatomies and surgical techniques. Thus, the purpose of the present study was to analyze the biomechanical performances of the intact, injured, and treated pelvises based on different physiological movements of the spine using finite element method. Three-dimensional musculoskeletal finite element models of the spine-pelvis-femur complex were developed. The intact pelvis, the rotationally unstable pelvis, and six types of pelvic fixation techniques were analyzed. Additionally, seven types of physiological movements of the spine were also considered. The results showed that the posterior iliosacral screws combined with lower and anterior plate (PIS-LAP) had good fixation stability, lower plate stress, and lower pelvic stress. However, the PIS-LAP increased the stress of the posterior iliosacral screws. The right lateral bending, left lateral bending, and flexion significantly affect all the biomechanical performances compared to the other physiological movements of the spine. The present study can provide engineers and surgeons with the understanding of the biomechanics of various fixation techniques during different physiological movements for the treatment of rotationally unstable pelvic fractures.
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Al-lami, Wael. "EFFECT OF EXERCISES ACCORDING TO THE BIOMECHANICS RECOMMENDATIONS FOR JAVELIN THROW." SCIENCE AND SPORT: current trends 8, no. 3 (September 1, 2020): 42–49. http://dx.doi.org/10.36028/2308-8826-2020-8-3-42-49.
Повний текст джерелаАнотація:
The purpose is to select and develop an exercise program adapted to the rate of contribution of biomechanical variables affecting the result in javelin throwing. Methods and organization of the research 1. Consideration of biomechanical variables in the development of javelin training process for the Iraqi national team has made a great contribution to sport performance. 2. We used data of a biomechanical analysis and a specialized physical fitness test to identify the levels of technical performance and physical fitness of the research participants. 3. The outcomes of the initial level of technical performance and specialized physical fitness enabled the development of models of technical performance and physical fitness with individual characteristics for participants in the experimental group. 4. Mathematical treatment of the educational experiment results revealed statistically significant differences between the experimental and control groups. Results Exercises designed by the researcher in accordance with the contribution of the variables to the result positively affect not only performance of participants in the experimental group, but also modification of important variables in the throwing technique. Conclusion Javelin throw is a complex coordinated motor action. Its result depends on both the level of specialized physical fitness and technical excellence of an athlete. A biomechanical analysis of the technique of research participants, computerized processing of the results of technique analysis, and the creation of an experimental training program for athletes based on comparison with the criteria of outstanding throwers’ technique enabled improvement of sport performance and biomechanical variables of the javelin throw technique by the end of the experiment.
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Kim, Heon-Jeong, and Bernard J. Martin. "Biodynamic Characteristics of Upper Limb Reaching Movements of the Seated Human Under Whole-Body Vibration." Journal of Applied Biomechanics 29, no. 1 (February 2013): 12–22. http://dx.doi.org/10.1123/jab.29.1.12.
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Simulation of human movements is an essential component for proactive ergonomic analysis and biomechanical model development (Chaffin, 2001). Most studies on reach kinematics have described human movements in a static environment, however the models derived from these studies cannot be applied to the analysis of human reach movements in vibratory environments such as in-vehicle operations. This study analyzes three-dimensional joint kinematics of the upper extremity in reach movements performed in static and specific vibratory conditions and investigates vibration transmission to shoulder, elbow, and hand along the body path during pointing tasks. Thirteen seated subjects performed reach movements to five target directions distributed in their right hemisphere. The results show similarities in the characteristics of movement patterns and reach trajectories of upper body segments for static and dynamic environments. In addition, vibration transmission through upper body segments is affected by vibration frequency, direction, and location of the target to be reached. Similarities in the pattern of movement trajectories revealed by filtering vibration-induced oscillations indicate that coordination strategy may not be drastically different in static and vibratory environments. This finding may facilitate the development of active biodynamic models to predict human performance and behavior under whole body vibration exposure.
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Supej, Matej, and H.-C. Holmberg. "Monitoring the Performance of Alpine Skiers with Inertial Motion Units: Practical and Methodological Considerations." Journal of Science in Sport and Exercise 3, no. 3 (May 25, 2021): 249–56. http://dx.doi.org/10.1007/s42978-021-00108-2.
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AbstractAlthough reliable feedback is crucial to improving the performance of competitive alpine skiers, the coach's eye may not be sensitive enough to detect small, but highly significant “mistakes”. Monitoring of the performance of alpine ski racers by inertial motion units (IMU) has proven to be of value in this context and here we summarize practical and methodological aspects of this approach. Methodologically, the IMUs employed should combine high sampling frequencies with minimal signal drift. The sensors should be positioned to sense the movement of the bones in a given body segment while being protected as much as possible against impact with the ski gates. The data obtained, often synchronized with input from Global Satellite Navigation Systems (GNSS), are usually refined utilizing advanced biomechanical models and other computerized approaches. In practice, the combination of inertial sensors and GNSS allows accurate monitoring of skiing kinematics (technique) and the movement of the skier’s center-of-mass, also allowing analysis of both whole-body vibrations (WBV) and loss of mechanical energy. Presentation of the findings to coaches and athletes can be facilitated by synchronizing them with video recordings. Recent advances in IMU technology, including miniaturization, wireless communication, direct storage of data in the cloud, and processing with artificial intelligence may allow these sensors, in-combination with GNSS, to become real-time virtual alpine ski coaches, perhaps the next step in the development of this sport.
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Su, Kuo-Chih, Kun-Hui Chen, Chien-Chou Pan, and Cheng-Hung Lee. "Biomechanical Evaluation of Cortical Bone Trajectory Fixation with Traditional Pedicle Screw in the Lumbar Spine: A Finite Element Study." Applied Sciences 11, no. 22 (November 10, 2021): 10583. http://dx.doi.org/10.3390/app112210583.
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Cortical bone trajectory (CBT) is increasingly used in spinal surgery. Although there are many biomechanical studies, the biomechanical effect of CBT in combination with traditional pedicle screws is not detailed. Therefore, the purpose of this study was to investigate the effects of the traditional pedicle screw and CBT screw implantation on the lumbar spine using finite element methods. Based on the combination of the traditional pedicle screw and the CBT system implanted into the lumbar spine, four finite element spinal lumbar models were established. The models were given four different load conditions (flexion, extension, lateral bending, and axial rotation), and the deformation and stress distribution on the finite element model were observed. The results show that there was no significant difference in the structural stability of the lumbar spine model between the traditional pedicle screw system and the CBT system. In addition, CBT may reduce stress on the endplate. Different movements performed by the model may have significant biomechanical effects on the spine and screw system. Clinical spinal surgeons may also consider using the CBT system in revision spinal surgery, which may contribute to smaller wounds.
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Drapała, Krzysztof, Kazimierz Pulaski, and Wojciech Blajer. "THE INFLUENCE OF ACTUATION MODELING ON THE ASSESSED JOINT REACTIONS IN BIOMECHANICAL SYSTEMS." Polish Journal of Sport and Tourism 20, no. 3 (September 1, 2013): 183–87. http://dx.doi.org/10.2478/pjst-2013-0016.
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Abstract Introduction. Human body biomechanical models are actuated either by net torques at the joints or individual muscle forces whose action around the joints results, by principle, in the net torques. In the model-based inverse dynamics simulation of human movements the assessed joint reactions depend substantially on the choice of the actuation model, which is discussed in the paper. Material and methods. Using the two actuation models, variant biomechanical models of the lower limb, decomposed from the whole human body, were developed. They were then used for the inverse dynamics simulation of a recorded one-leg jump on the force platform to assess time variations of controls (either net torques or muscle forces) and joint reactions. Results. The assessed joint reactions obtained using the model actuated by net torques are substantially different from those obtained by means of the model actuated by muscle forces. Conclusion. The joint reactions computed using the model actuated by net torques do not involve contribution of the tensile muscle forces to the internal loads, and they are therefore underestimated. Determination of joint reactions should thus be based on musculoskeletal models actuated by the muscle forces.
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Горбунов, Д. В., and Т. В. Гавриленко. "SIMULATION MODELING OF INVOLUNTARY HUMAN MOVEMENTS." Вестник КРАУНЦ. Физико-математические науки, no. 4 (December 25, 2019): 67–76. http://dx.doi.org/10.26117/2079-6641-2019-29-4-67-76.
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Разработана математическая и симуляционная модель для моделирования биомеханических движений конечности человека. Разработанный алгоритм модели базируется на биологическом представлении о включении и выключении в процессе удержания положения конечности отдельных мышц или их групп. Работа модели осуществляется за счет генерации случайных чисел (в математической форме симмуляционной модели отсутствуют статические величины). Сравнительный анализ экспериментальных и модельных данных показывает высокую эффективность работы симуляционной модели. Созданная симуляционная модель позволяет изучать принципы работы нервно-мышечной системы. Также модель является масштабируемой, что позволит в дальнейшем перейти к трехмерному моделированию для изучения механизмов самоорганизации биосистемы на уровне и нервно-мышечной системы, и центральной нервной системы. Mathematical and simulation model has been developed for modeling the biomechanical movements of a human limb. The developed model algorithm is based on the biological presentation and shutdown in the process of maintaining the positions of the final individual muscles or their groups. Work in models is due to statistical values. A comparative analysis of experimental and model data shows the high efficiency of the simulation model. The created simulation model allows to study the principles of the neuromuscular system. This model is scalable, which will allow us to switch to three-dimensional modeling to study the signs of self-organization of biosystems at the level of the neuromuscular system and central nervous system.
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Michalski, Julien, Andrea M. Green, and Paul Cisek. "Reaching decisions during ongoing movements." Journal of Neurophysiology 123, no. 3 (March 1, 2020): 1090–102. http://dx.doi.org/10.1152/jn.00613.2019.
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Neurophysiological studies suggest that when decisions are made between concrete actions, the selection process involves a competition between potential action representations in the same sensorimotor structures involved in executing those actions. However, it is unclear how such models can explain situations, often encountered during natural behavior, in which we make decisions while were are already engaged in performing an action. Does the process of deliberation characterized in classical studies of decision-making proceed the same way when subjects are deciding while already acting? In the present study, human subjects continuously tracked a target moving in the horizontal plane and were occasionally presented with a new target to which they could freely choose to switch at any time, whereupon it became the new tracked target. We found that the probability of choosing to switch increased with decreasing distance to the new target and increasing size of the new target relative to the tracked target, as well as when the direction to the new target was aligned (either toward or opposite) to the current tracking direction. However, contrary to our expectations, subjects did not choose targets that minimized the energetic costs of execution, as calculated by a biomechanical model of the arm. When the constraints of continuous tracking were removed in variants of the task involving point-to-point movements, the expected preference for lower cost choices was seen. These results are discussed in the context of current theories of nested feedback control, internal models of forward dynamics, and high-dimensional neural spaces. NEW & NOTEWORTHY Current theories of decision-making primarily address how subjects make decisions before executing selected actions. However, in our daily lives we often make decisions while already performing some action (e.g., while playing a sport or navigating through a crowd). To gain insight into how current theories can be extended to such “decide-while-acting” scenarios, we examined human decisions during continuous manual tracking and found some intriguing departures from how decisions are made in classical “decide-then-act” paradigms.
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Alfuth, Martin, Dieter Klein, Raphael Koch, and Dieter Rosenbaum. "Biomechanical Comparison of 3 Ankle Braces With and Without Free Rotation in the Sagittal Plane." Journal of Athletic Training 49, no. 5 (October 1, 2014): 608–16. http://dx.doi.org/10.4085/1062-6050-49.3.20.
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Context: Various designs of braces including hinged and nonhinged models are used to provide external support of the ankle. Hinged ankle braces supposedly allow almost free dorsiflexion and plantar flexion of the foot in the sagittal plane. It is unclear, however, whether this additional degree of freedom affects the stabilizing effect of the brace in the other planes of motion. Objective: To investigate the dynamic and passive stabilizing effects of 3 ankle braces, 2 hinged models that provide free plantar flexion–dorsiflexion in the sagittal plane and 1 ankle brace without a hinge. Design: Crossover study. Setting: University Movement Analysis Laboratory. Patients or Other Participants: Seventeen healthy volunteers (5 women, 12 men; age = 25.4 ± 4.8 years; height = 180.3 ± 6.5 cm; body mass = 75.5 ± 10.4 kg). Intervention(s): We dynamically induced foot inversion on a tilting platform and passively induced foot movements in 6 directions via a custom-built apparatus in 3 brace conditions and a control condition (no brace). Main Outcome Measure(s): Maximum inversion was determined dynamically using an in-shoe electrogoniometer. Passively induced maximal joint angles were measured using a torque and angle sensor. We analyzed differences among the 4 ankle-brace conditions (3 braces, 1 control) for each of the dependent variables with Friedman and post hoc tests (P < .05). Results: Each ankle brace restricted dynamic foot-inversion movements on the tilting platform as compared with the control condition, whereas only the 2 hinged ankle braces differed from each other, with greater movement restriction caused by the Ankle X model. Passive foot inversion was reduced with all ankle braces. Passive plantar flexion was greater in the hinged models as compared with the nonhinged brace. Conclusions: All ankle braces showed stabilizing effects against dynamic and passive foot inversion. Differences between the hinged braces and the nonhinged brace did not appear to be clinically relevant.
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Mebarki, Salah, Benaoumeur Aour, Malachanne Etienne, Franck Jourdan, Abdel Hakem Belaghit, and Abdelkader Gasmi. "Numerical Study of the Biomechanical Behaviour of the Different Implantation Methods of the Reverse Shoulder Replacement." Journal of Biomimetics, Biomaterials and Biomedical Engineering 43 (November 2019): 54–66. http://dx.doi.org/10.4028/www.scientific.net/jbbbe.43.54.
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Despite the widespread use of reverse total shoulder arthroplasty, there is still a problem of conflict between the polyethylene cup of the prosthesis and the scapula, which over time causes the phenomenon of notching. In order to circumvent this problem correctly, several innovations have been proposed regard to the implementation method. In this context, the aim of this work is to study the biomechanical behavior of new implantation methods using different glenoid configurations in order to avoid the notching phenomenon between the cup and the scapula. The study was performed using virtual prototypes of the shoulder prosthesis assembly. Using CT scan images, three-dimensional models of shoulder bones were reconstructed. The implantation of the prosthesis in the three-dimensional model was performed in collaboration with an experienced surgeon from the Caduceus Clinic (Oran, Algeria). The numerical models were imported to finite element calculation software. After the validation of the numerical model using the literature results, we assessed the biomechanical behavior of four implantation methods under the same boundary conditions and abduction movements. From the obtained results, it was found that among the proposed methods, the BIO-SR lateralization method offers significant biomechanical advantages in terms of the forces applied to the glenoid during the abduction movement.
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Ciunel, Stefaniţă, and Dragoş Laurenţiu Popa. "Analysis and Dynamic of Human Cranio-Cervical Complex Movements." Applied Mechanics and Materials 809-810 (November 2015): 1187–92. http://dx.doi.org/10.4028/www.scientific.net/amm.809-810.1187.
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Concerned challenge of road safety in research and development, most automotive companies develops more than 50 years, technologies that improve the safety of their vehicles presented. Most research is based on studies carried out in the laboratories accidentology and analysis of human behavior to improve biofidelity test these models in order to develop the most effective equipment to investigate real-life situations that can arise on the road. There are programs on road safety designed around four key areas: prevention, correction, protection and awareness. If, in the best case to protect in case of an incident is crucial to avoid the accident is an absolute priority. Studies show that human error is the basis of 80% of all cases occurring in road events [1]. Today, automotive companies never cease to develop new safety devices which prevent an accident or to protect the passengers. Elections conducted safety relies on a greater degree of prevention, more anticipation, the driver is still the factor responsible for the act of driving Extremely complex, however, and the body structure and reactivity to shock [2]. Shock response is broad and consists of biomechanical response and neuro major spending in the immediate care and rehabilitation.
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Ravera, Emiliano P., Marcos J. Crespo, and Paola A. Catalfamo Formento. "A subject-specific integrative biomechanical framework of the pelvis for gait analysis." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 232, no. 11 (October 3, 2018): 1083–97. http://dx.doi.org/10.1177/0954411918803125.
Повний текст джерелаАнотація:
Analysis of the human locomotor system using rigid-body musculoskeletal models has increased in the biomechanical community with the objective of studying muscle activations of different movements. Simultaneously, the finite element method has emerged as a complementary approach for analyzing the mechanical behavior of tissues. This study presents an integrative biomechanical framework for gait analysis by linking a musculoskeletal model and a subject-specific finite element model of the pelvis. To investigate its performance, a convergence study was performed and its sensitivity to the use of non-subject-specific material properties was studied. The total hip joint force estimated by the rigid musculoskeletal model and by the finite element model showed good agreement, suggesting that the integrative approach estimates adequately (in shape and magnitude) the hip total contact force. Previous studies found movements of up to 1.4 mm in the anterior–posterior direction, for single leg stance. These results are comparable with the displacement values found in this study: 0–0.5 mm in the sagittal axis. Maximum von Mises stress values of approximately 17 MPa were found in the pelvic bone. Comparing this results with a previous study of our group, the new findings show that the introduction of muscular boundary conditions and the flexion–extension movement of the hip reduce the regions of high stress and distributes more uniformly the stress across the pelvic bone. Thus, it is thought that muscle force has a relevant impact in reducing stresses in pelvic bone during walking of the finite element model proposed in this study. Future work will focus on including other deformable structures, such as the femur and the tibia, and subject-specific material properties.
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Kaminska, Marianna, Valerii Degtuar, and Oleksandr Yaresko. "Mathematical modeling of the chest, its funnel-shaped deformation and thoracoplasty." ORTHOPAEDICS, TRAUMATOLOGY and PROSTHETICS, no. 2 (October 12, 2021): 17–22. http://dx.doi.org/10.15674/0030-59872021217-22.
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The most common method of treating of the congenital funnel-shaped chest is thoracoplasty method by D. Nuss. During this surgery, a significant mechanical effect is created on the ribs, sternum, spinal column, which act instantly and continuously for a long time and create new biomechanical conditions for the «chest – rib – spine» system. Objective. To construct a functional model of the chest with a spinal column, which takes into account the movements in the costal-vertebral joints, it allows modeling the funnel-shaped deformation in conditions close to the reality, its operative correction, predicting the results and choosing the optimal parameters of thoracoplasty. Methods. Normal and funnel-shaped chest models based on the articular connection of the ribs to the spine were created using SolidWorks. The main calculations were made using the ANSYS program. To estimate the stress-strain state (SSS), stresses are selected by Mises. Results. The created dynamic mathematical model of the chest makes it possible to conduct a reliable analysis of the biomechanical interaction of the plate with the chest, to analyze the stress-strain state of the constructed models in the norm, with and without taking into account the movements in the costal-vertebral joints. In addition, it allows to simulate the operation by D. Nuss and to study the biomechanical changes in conditions close to reality, occurring in the «chest – rib – spine» system, to determine the areas of maximum loads and safety boundaries. Conclusions. The reproduction of articular ribs rotation in the dynamic model changes the picture of the SSS distribution. In the case of modeling the correction of funnel-shaped deformation of the chest by the method by D. Nuss, the largest zone of stress concentration was found on the outer posterior surface of the sixth pair of ribs. The most tense vertebrae were ThV– ThVI, but the maximum values did not exceed the permissible values. In the case of a lower plate conduction, the correction is achieved with better SSS values in the higher elements of the «chest – ribs – spine» system.
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Scarpa, Elena, and Roberto Mayor. "Collective cell migration in development." Journal of Cell Biology 212, no. 2 (January 18, 2016): 143–55. http://dx.doi.org/10.1083/jcb.201508047.
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During embryonic development, tissues undergo major rearrangements that lead to germ layer positioning, patterning, and organ morphogenesis. Often these morphogenetic movements are accomplished by the coordinated and cooperative migration of the constituent cells, referred to as collective cell migration. The molecular and biomechanical mechanisms underlying collective migration of developing tissues have been investigated in a variety of models, including border cell migration, tracheal branching, blood vessel sprouting, and the migration of the lateral line primordium, neural crest cells, or head mesendoderm. Here we review recent advances in understanding collective migration in these developmental models, focusing on the interaction between cells and guidance cues presented by the microenvironment and on the role of cell–cell adhesion in mechanical and behavioral coupling of cells within the collective.
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Kohout, J., G. J. Clapworthy, Y. Zhao, Y. Tao, G. Gonzalez-Garcia, F. Dong, H. Wei, and E. Kohoutová. "Patient-specific fibre-based models of muscle wrapping." Interface Focus 3, no. 2 (April 6, 2013): 20120062. http://dx.doi.org/10.1098/rsfs.2012.0062.
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In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures.
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Vatsal, Vighnesh, and Guy Hoffman. "The Wearable Robotic Forearm: Design and Predictive Control of a Collaborative Supernumerary Robot." Robotics 10, no. 3 (July 16, 2021): 91. http://dx.doi.org/10.3390/robotics10030091.
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This article presents the design process of a supernumerary wearable robotic forearm (WRF), along with methods for stabilizing the robot’s end-effector using human motion prediction. The device acts as a lightweight “third arm” for the user, extending their reach during handovers and manipulation in close-range collaborative activities. It was developed iteratively, following a user-centered design process that included an online survey, contextual inquiry, and an in-person usability study. Simulations show that the WRF significantly enhances a wearer’s reachable workspace volume, while remaining within biomechanical ergonomic load limits during typical usage scenarios. While operating the device in such scenarios, the user introduces disturbances in its pose due to their body movements. We present two methods to overcome these disturbances: autoregressive (AR) time series and a recurrent neural network (RNN). These models were used for forecasting the wearer’s body movements to compensate for disturbances, with prediction horizons determined through linear system identification. The models were trained offline on a subset of the KIT Human Motion Database, and tested in five usage scenarios to keep the 3D pose of the WRF’s end-effector static. The addition of the predictive models reduced the end-effector position errors by up to 26% compared to direct feedback control.
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Anglin, C., and U. P. Wyss. "Review of arm motion analyses." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 214, no. 5 (May 1, 2000): 541–55. http://dx.doi.org/10.1243/0954411001535570.
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Interest in arm movements has increased tremendously in recent years. This interest has been motivated by different goals: the desire for a more scientific approach to replacement or support of the joints of the upper limb, the need for input to biomechanical computer models, and the clinical interest in comparing normal movements with pathological movements. The availability of commercial marker-tracking systems has facilitated achieving these goals. However, the complex nature of arm movements and the lack of standardized movements raises many challenges. In comparison with gait analysis, few arm motion analyses have been conducted. The purpose of this review is to aid researchers and clinicians interested in conducting an arm motion study in choosing the appropriate methodology. This is accomplished both by describing the methods used in past investigations and by highlighting important findings. Due to the variety of research goals, there is sometimes more than one appropriate method and the choice is left to the reader. Nevertheless, since it is extremely desirable to record and express the data in a standardized way, standardization proposals are described. This review, which focuses on methodology rather than results, addresses the following topics: motivations and tasks studied, tracking methods, the shoulder complex, joint centres and rotation axes, marker positions, coordinate system definitions, terminology and rotations, accuracy, and presentation methods.
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Ionescu, Mircea, and Ileana Constanţa Roșca. "Contribution to Analyze and Modeling of the Hand." Applied Mechanics and Materials 245 (December 2012): 63–67. http://dx.doi.org/10.4028/www.scientific.net/amm.245.63.
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The importance of joint integrity is a priority of the hand and wrist joints mobility is crucial for any individual. Motion control is achieved by the somatic nervous system composed of those formations which are designed to integrate body in the external environment, to achieve body relationship with this environment. Dynamic biomechanical models serve for quantitative analysis required in planning surgery on tendons [6] or to assess the transfer of nervous signals controlling the effectors [5]. Some others are dedicated to model various operations for design and implementation of the prosthetic components [13]. Recent models have approximately the same configuration: changing dimensional structure is not taken into account, but only the resulting physiological movement and rotation are analyzed for a single predominantly degree of freedom around a defined axis. Many scientists have tried over time to reproduce the hand kinematics, but not so many are those who have tried to design a guiding hand mechanism to reproduce its natural movements. The aim of this paper is to achieve the cinematic scheme of such a mechanism, able to lead fingers on path as possible as close to their natural movements.
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Beppi, Carolina, Marco Penner, Dominik Straumann, and Stefan Yu Bögli. "A non-invasive biomechanical model of mild TBI in larval zebrafish." PLOS ONE 17, no. 5 (May 27, 2022): e0268901. http://dx.doi.org/10.1371/journal.pone.0268901.
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A mild traumatic brain injury is a neurological dysfunction caused by biomechanical forces transmitted to the brain in physical impacts. The current understanding of the neuropathological cascade resulting in the manifested clinical signs and symptoms is limited due to the absence of sensitive brain imaging methods. Zebrafish are established models for the reproduction and study of neurobiological pathologies. However, all available models mostly recreate moderate-to-severe focal injuries in adult zebrafish. The present work has induced a mild brain trauma in larval zebrafish through a non-invasive biomechanical approach. A custom-made apparatus with a commercially available motor was employed to expose larvae to rapidly decelerating linear movements. The neurophysiological changes following concussion were assessed through behavioural quantifications of startle reflex locomotor distance and habituation metrics. Here we show that the injury was followed, within five minutes, by a transient anxiety state and CNS dysfunction manifested by increased startle responsivity with impaired startle habituation, putatively mirroring the human clinical sign of hypersensitivity to noise. Within a day after the injury, chronic effects arose, as evidenced by an overall reduced responsivity to sensory stimulation (lower amplitude and distance travelled along successive stimuli), reflecting the human post-concussive symptomatology. This study represents a step forward towards the establishment of a parsimonious (simple, less ethically concerning, yet sensitive) animal model of mild TBI. Our behavioural findings mimic aspects of acute and chronic effects of human concussion, which warrant further study at molecular, cellular and circuit levels. While our model opens wide avenues for studying the underlying cellular and molecular pathomechanisms, it also enables high-throughput testing of therapeutic interventions to accelerate post-concussive recovery.
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Mahato, Niladri Kumar. "Reviewing Complex Static-Dynamic Concepts of Spine Stability: Does the Spine Care Only to Be Stiff to Be Stable?" Journal of Morphological Sciences 36, no. 04 (August 8, 2019): 309–16. http://dx.doi.org/10.1055/s-0039-1688970.
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Background Changes in the load-displacement relationship in spine segments suggesting alterations in biomechanical stiffness may not yield significant clinical information. Changes in Spine stiffness may arise secondary to neuro-muscular adjustments in the para-spinal muscles and may not be associated with physical anatomical laxity or motion restrictions at segmental articulations. Segmental stiffness may vary dynamically at different zones within the range-of-motion, suggesting a non-linear load-displacement relationship during motion. There is no linear, mechanistic relationship between spine pain and biomechanical markers of spine instability. Objective To review diagnostic assessment approaches of spine instability based on palpatory techniques, end-of-range radiography and imaging in light of our current understanding of biomechanical spine stability. Method The Medline and PubMed databases were screened for primary medical and engineering research articles and reviews on spine stability. Information related to bio-mechanical concepts and clinical decision-making were extracted and synthesized. Spine stability was described in two classical forms, the structural (anatomical) and the functional (physiological), the implications of static and dynamic instability was described in terms of biomechanical and mathematical models used to understand etiology of non-specific back pain. Results Evidence supports the view that dynamic adaptations in the load-displacement relationship of the spine may be resistive or assistive, depending on task-specific movements. Diagnosis of instability is based on structural and functional integrity of the segments in a static or dynamic context. Conclusion Development of specific criteria to define clinical spine stability, compatible with system-based biomechanical concept of spine stiffness, is an ongoing topic in clinical and basic science research.
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Ciunel, Stefanita, Dragos Laurentiu Popa, and Nicolae Dumitru. "Studies about Movement Biofidelity of a Dummy Neck Used in an Impact Testing Device." Applied Mechanics and Materials 371 (August 2013): 539–43. http://dx.doi.org/10.4028/www.scientific.net/amm.371.539.
Повний текст джерелаАнотація:
The paper presents the studies made on a similar biomechanical system composed by neck, head and thorax bones. The main movements analyzed were: axial rotation (left-right), lateral bending (left-right) and flexion-extension movement. After simulation was obtained the entire mechanical behavior based on data tables or diagrams. The models were defined in a CAD environment which includes Adams algorithm for dynamic simulations. The virtual models were obtained starting with CT images made on a living human subject. That virtual model composed by neck and head can be included in complex system (as a car system) and supposed to impact simulations (virtual crash tests). Also was developed a mathematical model based on Lagrange equations for a frontal impact testing cervical system. Our research team built main components of a testing device for dummy car crash neck-head system using anatomical data.
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Ozhohan, Roman, Mykola M. Rozhko, Zinoviy R. Ozhogan, Roman M. Khopta, and Lidiia Miziuk. "MODERN METHODS OF PATIENTS TREATMENT WITH DENTITION DEFECTS COMBINED WITH FUNCTIONAL DISORDERS OF THE TEMPOROMANDIBULAR JOINT." Wiadomości Lekarskie 73, no. 10 (2020): 2241–45. http://dx.doi.org/10.36740/wlek202010126.
Повний текст джерелаАнотація:
The aim: The purpose of the research was to increase the efficiency of treatment at patients with dentition defects and functional disorders of the temporomandibular joint. Materials and methods: We examined 140 patients aged from 25 to 65 years with functional disorders of the temporomandibular joint, analysed there diagnostic models in the articulator and 3D scanner, used radiographic methods of examination and condylography. Results: The results of the conducted studies showed that in the 1st group, the biomechanical parameters of temporomandibular joint movements before treatment were significantly lower: 6,4 ± 0,2 mm and 6,8 ± 0,2 mm for right and left temporomandibular joint during protrusion movements; 7,8 ± 0,1 mm and 7,9 ± 0,2 mm during vertical movements; 6,7 ± 0,1 mm and 6,5 ± 0,2 mm during transversal movements. After 12 month of complex and prosthetic treatment with a help of non-removable dentures the magnitude of movements remains at the achieved level at all excursions. As a result, proposed by us comprehensive treatment of functional disorders of the temporomandibular joint is carried out in stages. The proposed design of an individual tire makes it possible to gradually increase the bite height and perfectly forms the occlusal ratio. After 6 and 12 months of the proposed treatment, we have found that the indicators of vertical and protrusion movements of articular heads at patients of 2nd group were significantly better than before treatment. Conclusions: The proposed design of an individual tire makes it possible to gradually increase the bite height and perfectly forms the occlusal ratio.
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Daggett, Matthew C., Kevin A. Witte, Dimitrije Cabarkapa, Damjana V. Cabarkapa, and Andrew C. Fry. "Evidence-Based Data Models for Return-to-Play Criteria after Anterior Cruciate Ligament Reconstruction." Healthcare 10, no. 5 (May 18, 2022): 929. http://dx.doi.org/10.3390/healthcare10050929.
Повний текст джерелаАнотація:
The anterior cruciate ligament (ACL) tear is one of the most common knee injuries in sports that require side-to-side pivoting movements. While the timeline and specific goals during rehabilitation protocols may vary, ACL reconstruction (ACLR) is the preferred procedure necessary to return these athletes to their respective field of play. However, there are no validated guidelines that define a specific timepoint when it is safe for an athlete to return-to-play, as functional movement deficit may be present much longer than six months post ACLR. A retrospective cross-sectional analysis was conducted on 33 subjects that underwent ACLR. As a part of standard of care, each subject completed a movement screening protocol at a singular timepoint during their rehabilitation process. An innovative three-dimensional markerless motion capture system was used to obtain three algorithm-derived biometric variables: mobility, alignment, and readiness. Significant gradual improvements in mobility and readiness were observed throughout a 3–6-month post ACLR procedure period. When examining the data trends, it was obvious that not all patients responded identically to treatment plans provided by clinical professionals. Therefore, the findings of the present study suggest that the decision regarding when it is safe to return to play needs to be determined on an individual basis.
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Anderson, Philip S. L., and Mark W. Westneat. "A biomechanical model of feeding kinematics forDunkleosteus terrelli(Arthrodira, Placodermi)." Paleobiology 35, no. 2 (2009): 251–69. http://dx.doi.org/10.1666/08011.1.
Повний текст джерелаАнотація:
Biomechanical models illustrate how the principles of physics and physiology determine function in organisms, allowing ecological inferences and functional predictions to be based on morphology. Dynamic lever and linkage models of the mechanisms of the jaw and skull during feeding in fishes predict function from morphology and have been used to compare the feeding biomechanics of diverse fish groups, including fossil taxa, and to test ideas in ecological morphology. Here we perform detailed computational modeling of the four-bar linkage mechanism in the skull and jaw systems ofDunkleosteus terrelli, using software that accepts landmark morphological data to simulate the movements and mechanics of the skull and jaws during prey capture. The linkage system is based on the quadrate and cranio-thoracic joints: Cranial elevation around the cranio-thoracic joint forces the quadrate joint forward, which, coupled with a jaw depressor muscle connecting the jaw to the thoracic shield, causes the jaw to rotate downward during skull expansion. Results show a high speed transmission for jaw opening, producing a rapid expansion phase similar to that in modern fishes that use suction during prey capture. During jaw closing, the model computes jaw and skull rotation and a series of mechanical metrics including effective mechanical advantage of the jaw lever and kinematic transmission of the skull linkage system. Estimates of muscle cross-sectional area based on the largest of five specimens analyzed allow the bite force and strike speed to be estimated. Jaw-closing muscles ofDunkleosteuspowered an extraordinarily strong bite, with an estimated maximal bite force of over 6000 N at the jaw tip and more than 7400 N at the rear dental plates, for a large individual (10 m total length). This bite force capability is among the most powerful bites in animals. The combination of rapid gape expansion and powerful bite meant thatDunkleosteus terrellicould both catch elusive prey and penetrate protective armor, allowing this apex predator to potentially eat anything in its ecosystem, including other placoderms.
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Campoli, Gianni, Bart Bolsterlee, Frans van der Helm, Harrie Weinans, and Amir A. Zadpoor. "Effects of densitometry, material mapping and load estimation uncertainties on the accuracy of patient-specific finite-element models of the scapula." Journal of The Royal Society Interface 11, no. 93 (April 6, 2014): 20131146. http://dx.doi.org/10.1098/rsif.2013.1146.
Повний текст джерелаАнотація:
Patient-specific biomechanical models including patient-specific finite-element (FE) models are considered potentially important tools for providing personalized healthcare to patients with musculoskeletal diseases. A multi-step procedure is often needed to generate a patient-specific FE model. As all involved steps are associated with certain levels of uncertainty, it is important to study how the uncertainties of individual components propagate to final simulation results. In this study, we considered a specific case of this problem where the uncertainties of the involved steps were known and the aim was to determine the uncertainty of the predicted strain distribution. The effects of uncertainties of three important components of patient-specific models, including bone density, musculoskeletal loads and the parameters of the material mapping relationship on the predicted strain distributions, were studied. It was found that the number of uncertain components and the level of their uncertainty determine the uncertainty of simulation results. The ‘average’ uncertainty values were found to be relatively small even for high levels of uncertainty in the components of the model. The ‘maximum’ uncertainty values were, however, quite high and occurred in the areas of the scapula that are of the greatest clinical relevance. In addition, the uncertainty of the simulation result was found to be dependent on the type of movement analysed, with abduction movements presenting consistently lower uncertainty values than flexion movements.
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LIN, CHIEN-JU, PO-CHOU LIN, FONG-CHIN SU, and KAI-NAN AN. "BIOMECHANICS OF WHEELCHAIR PROPULSION." Journal of Mechanics in Medicine and Biology 09, no. 02 (June 2009): 229–42. http://dx.doi.org/10.1142/s0219519409002948.
Повний текст джерелаАнотація:
With progress of modern technology, manually-propelled wheelchairs are still of importance for individuals with mobility impairments. The repeated wheelchair propulsion and strenuous daily activities cause high loads and thus injuries on the upper extremity joints. Over the past few years, a considerable number of studies have been made on biomechanical analysis of wheelchair propulsion and wheelchair-related activities. Thorough investigation of biomechanics during wheelchair propulsion enhances comprehension of mechanism of injuries and provides information to improve wheelchair design and fitting. Numerous investigations have been made to demonstrate factors which cause low effectiveness of force application and inefficiency of movements. Emphasis was also placed on developing analytical models to simulate wheelchair propulsion.
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Myer, Gregory D., Nathaniel A. Bates, Christopher A. DiCesare, Kim D. Barber Foss, Staci M. Thomas, Samuel C. Wordeman, Dai Sugimoto, et al. "Reliability of 3-Dimensional Measures of Single-Leg Drop Landing Across 3 Institutions: Implications for Multicenter Research for Secondary ACL-Injury Prevention." Journal of Sport Rehabilitation 24, no. 2 (May 2015): 198–209. http://dx.doi.org/10.1123/jsr.2014-0237.
Повний текст джерелаАнотація:
Context:Due to the limitations of single-center studies in achieving appropriate sampling with relatively rare disorders, multicenter collaborations have been proposed to achieve desired sampling levels. However, documented reliability of biomechanical data is necessary for multicenter injury-prevention studies and is currently unavailable.Objective:To measure the reliability of 3-dimensional (3D) biomechanical waveforms from kinetic and kinematic variables during a single-leg landing (SLL) performed at 3 separate testing facilities.Design:Multicenter reliability study.Setting:3 laboratories.Patients:25 female junior varsity and varsity high school volleyball players who visited each facility over a 1-mo period.Intervention:Subjects were instrumented with 43 reflective markers to record 3D motion as they performed SLLs. During the SLL the athlete balanced on 1 leg, dropped down off of a 31-cm-high box, and landed on the same leg. Kinematic and kinetic data from both legs were processed from 2 trials across the 3 laboratories.Main Outcome Measures:Coefficients of multiple correlations (CMC) were used to statistically compare each joint angle and moment waveform for the first 500 ms of landing.Results:Average CMC for lower-extremity sagittal-plane motion was excellent between laboratories (hip .98, knee .95, ankle .99). Average CMC for lower-extremity frontal-plane motion was also excellent between laboratories (hip .98, knee .80, ankle .93). Kinetic waveforms were repeatable in each plane of rotation (3-center mean CMC ≥.71), while knee sagittal-plane moments were the most consistent measure across sites (3-center mean CMC ≥.94).Conclusions:CMC waveform comparisons were similar relative to the joint measured to previously published reports of between-sessions reliability of sagittal- and frontal-plane biomechanics performed at a single institution. Continued research is needed to further standardize technology and methods to help ensure that highly reliable results can be achieved with multicenter biomechanical screening models.
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Ferrario, Andrea, Andrey Palyanov, Stella Koutsikou, Wenchang Li, Steve Soffe, Alan Roberts, and Roman Borisyuk. "From decision to action: Detailed modelling of frog tadpoles reveals neuronal mechanisms of decision-making and reproduces unpredictable swimming movements in response to sensory signals." PLOS Computational Biology 17, no. 12 (December 13, 2021): e1009654. http://dx.doi.org/10.1371/journal.pcbi.1009654.
Повний текст джерелаАнотація:
How does the brain process sensory stimuli, and decide whether to initiate locomotor behaviour? To investigate this question we develop two whole body computer models of a tadpole. The “Central Nervous System” (CNS) model uses evidence from whole-cell recording to define 2300 neurons in 12 classes to study how sensory signals from the skin initiate and stop swimming. In response to skin stimulation, it generates realistic sensory pathway spiking and shows how hindbrain sensory memory populations on each side can compete to initiate reticulospinal neuron firing and start swimming. The 3-D “Virtual Tadpole” (VT) biomechanical model with realistic muscle innervation, body flexion, body-water interaction, and movement is then used to evaluate if motor nerve outputs from the CNS model can produce swimming-like movements in a volume of “water”. We find that the whole tadpole VT model generates reliable and realistic swimming. Combining these two models opens new perspectives for experiments.
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Schumacher, C., M. Sharbafi, A. Seyfarth, and C. Rode. "Biarticular muscles in light of template models, experiments and robotics: a review." Journal of The Royal Society Interface 17, no. 163 (February 2020): 20180413. http://dx.doi.org/10.1098/rsif.2018.0413.
Повний текст джерелаАнотація:
Leg morphology is an important outcome of evolution. A remarkable morphological leg feature is the existence of biarticular muscles that span adjacent joints. Diverse studies from different fields of research suggest a less coherent understanding of the muscles’ functionality in cyclic, sagittal plane locomotion. We structured this review of biarticular muscle function by reflecting biomechanical template models, human experiments and robotic system designs. Within these approaches, we surveyed the contribution of biarticular muscles to the locomotor subfunctions ( stance , balance and swing ). While mono- and biarticular muscles do not show physiological differences, the reviewed studies provide evidence for complementary and locomotor subfunction-specific contributions of mono- and biarticular muscles. In stance , biarticular muscles coordinate joint movements, improve economy (e.g. by transferring energy) and secure the zig-zag configuration of the leg against joint overextension. These commonly known functions are extended by an explicit role of biarticular muscles in controlling the angular momentum for balance and swing . Human-like leg arrangement and intrinsic (compliant) properties of biarticular structures improve the controllability and energy efficiency of legged robots and assistive devices. Future interdisciplinary research on biarticular muscles should address their role for sensing and control as well as non-cyclic and/or non-sagittal motions, and non-static moment arms.
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POTKONJAK, VELJKO. "ROBOTIC HANDWRITING." International Journal of Humanoid Robotics 02, no. 01 (March 2005): 105–24. http://dx.doi.org/10.1142/s021984360500034x.
Повний текст джерелаАнотація:
Handwriting has always been considered an important human task, and accordingly it has attracted the attention of researchers working in biomechanics, physiology, and related fields. There exist a number of studies on this area. This paper considers the human–machine analogy and relates robots with handwriting. The work is two-fold: it improves the knowledge in biomechanics of handwriting, and introduces some new concepts in robot control. The idea is to find the biomechanical principles humans apply when resolving kinematic redundancy, express the principles by means of appropriate mathematical models, and then implement them in robots. This is a step forward in the generation of human-like motion of robots. Two approaches to redundancy resolution are described: (i) "Distributed Positioning" (DP) which is based on a model to represent arm motion in the absence of fatigue, and (ii) the "Robot Fatigue" approach, where robot movements similar to the movements of a human arm under muscle fatigue are generated. Both approaches are applied to a redundant anthropomorphic robot arm performing handwriting. The simulation study includes the issues of legibility and inclination of handwriting. The results demonstrate the suitability and effectiveness of both approaches.
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Zhang, Xudong, Jinjun Xiong, and Angela M. Bishop. "Effects of Load and Speed on Lumbar Vertebral Kinematics during Lifting Motions." Human Factors: The Journal of the Human Factors and Ergonomics Society 45, no. 2 (June 2003): 296–306. http://dx.doi.org/10.1518/hfes.45.2.296.27242.
Повний текст джерелаАнотація:
This experimental study investigated the effects of load magnitude and movement speed on lumbar vertebral kinematics during lifting task performance. Ten participants performed sagittally symmetric lifting movements with systematically varied load using either a normal or a faster-than-normal speed. Skin-surface markers were strategically placed over the participants' spinous processes and other landmarks representing major body joints and were recorded during the movements by a motion capture system. The center of rotation (COR) locations and segmental movement profiles for lumbar vertebrae L2 to L5 were derived and analyzed. Results suggested that (a) the COR locations and vertebral angular displacement were not significantly affected by the speed or load variation; (b) a faster speed tended to shorten the time to complete the acceleration for all the lumbar vertebrae considered; and (c) the load increase incurred a tendency for the L5 to complete the primary displacement in a briefer time while enduring greater peak acceleration and velocity. The findings lead to a better understanding of the relation between lifting dynamics and spinal motion. Potential applications of this research include the development of more accurate biomechanical models and software tools for depicting spinal motions and quantifying low-back stress.
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Wilson, R. J., B. A. Skierczynski, S. Blackwood, R. Skalak, and W. B. Kristan. "Mapping motor neurone activity to overt behaviour in the leech: internal pressures produced during locomotion." Journal of Experimental Biology 199, no. 6 (June 1, 1996): 1415–28. http://dx.doi.org/10.1242/jeb.199.6.1415.
Повний текст джерелаАнотація:
Several behaviour patterns have been studied in the leech at both the kinematic and neuronal levels. However, very little is known about how patterns of motor neurone activity map to actual movements. Internal pressure is an essential biomechanical property in this process, being responsible for producing the rigidity and posture that allow the directed delivery of forces produced by muscle contraction. To obtain a better understanding of the biomechanical processes involved in movement of the leech, we have measured the internal pressure of the animal by placing catheters through the body wall and into the gut of intact animals showing normal patterns of behaviour. Each type of behaviour had a characteristic pressure waveform. The elongation phase of crawling produced a rapid increase in pressure that peaked when midbody segments were maximally elongated. The pressure produced during the contraction phase of crawling depended on the type of crawl, only inchworm crawling producing a second peak. Whole-body shortening in response to a head poke also produced a pressure peak, but it had a faster rise time. Swimming produced the largest pressure, which was marked by a large sustained increase that fluctuated phasically with undulations of the body. Dual pressure recordings using two catheters demonstrated that pressure was not uniform along the length of the leech, indicating that the body cavity is functionally compartmentalised. Injecting fluid into the gut via a recording catheter allowed us to determine the effects of increasing internal volume on pressure. In line with previous predictions made using an abstract biomechanical model of the leech hydroskeleton, we found that an increase in the volume caused a reduction in the pressure. We are in the process of constructing a more realistic biomechanical model of the leech, based on actual data reported elsewhere. The results in this paper will provide key tests for refining these models.
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Martin-Fernandez, Elena, Ignacio Gonzalez-Gonzalez, Hector deLlanos-Lanchares, Mario Andres Mauvezin-Quevedo, Aritza Brizuela-Velasco, and Angel Alvarez-Arenal. "Mandibular Flexure and Peri-Implant Bone Stress Distribution on an Implant-Supported Fixed Full-Arch Mandibular Prosthesis: 3D Finite Element Analysis." BioMed Research International 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/8241313.
Повний текст джерелаАнотація:
Purpose. The purpose of this study was to evaluate and compare the effect of three mandibular full-arch superstructures on the peri-implant bone stress distribution during mandibular flexure caused by mid-opening (27 mm) and protrusion mandibular movements. Materials and Methods. Three-dimensional finite element models were created simulating six osseointegrated implants in the jawbone. One model simulated a 1-piece framework and the other simulated 2-piece and 3-piece frameworks. Muscle forces with definite direction and magnitude were exerted over areas of attachment to simulate multiple force vectors of masticatory muscles during mandibular protrusion and opening. Results. During the movement of 27.5 mm jaw opening, the 1-piece and 3-piece superstructures showed the lowest values of bone stress around the mesial implants, gradually increasing towards the distal position. During the protrusion movement, bone stress increased compared to opening for any implant situation and for a divided or undivided framework. The 3-piece framework showed the highest values of peri-implant bone stress, regardless of the implant situation. Conclusions. The undivided framework provides the best biomechanical environment during mandibular protrusion and opening. Protrusion movement increases the peri-implant bone stress. The most mesial implants have the lowest biomechanical risk.