Artículos de revistas: "Human locomotion biomechanics and energetics"

1

Takahashi, Kota Z., Rebecca L. Krupenevich, Amy L. Lenz, Luke A. Kelly, Michael J. Rainbow y Jason R. Franz. "Mechanics and Energetics of Human Feet: A Contemporary Perspective for Understanding Mobility Impairments in Older Adults". Biomechanics 2, n.º 4 (23 de septiembre de 2022): 494–99. http://dx.doi.org/10.3390/biomechanics2040038.

Texto completo

Resumen

Much of our current understanding of age-related declines in mobility has been aided by decades of investigations on the role of muscle–tendon units spanning major lower extremity joints (e.g., hip, knee and ankle) for powering locomotion. Yet, mechanical contributions from foot structures are often neglected. This is despite the emerging evidence of their critical importance in youthful locomotion. With the rapid growth in the field of human foot biomechanics over the last decade, our theoretical knowledge of young asymptomatic feet has transformed, from long-held views of the foot as a stiff lever and a shock absorber to that of a versatile system that can modulate mechanical power and energy output to accommodate various locomotor task demands. In this perspective review, we predict that the next set of impactful discoveries related to locomotion in older adults will emerge by integrating the novel tools and approaches that are currently transforming the field of human foot biomechanics. By illuminating the functions of the feet in older adults, we envision that future investigations will refine our mechanistic understanding of mobility deficits affecting our aging population, which may ultimately inspire targeted interventions to rejuvenate the mechanics and energetics of locomotion.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Lindstedt, Stan L., Patrick M. Mineo y Paul J. Schaeffer. "Animal galloping and human hopping: an energetics and biomechanics laboratory exercise". Advances in Physiology Education 37, n.º 4 (diciembre de 2013): 377–83. http://dx.doi.org/10.1152/advan.00045.2013.

Texto completo

Resumen

This laboratory exercise demonstrates fundamental principles of mammalian locomotion. It provides opportunities to interrogate aspects of locomotion from biomechanics to energetics to body size scaling. It has the added benefit of having results with robust signal to noise so that students will have success even if not “meticulous” in attention to detail. First, using respirometry, students measure the energetic cost of hopping at a “preferred” hop frequency. This is followed by hopping at an imposed frequency half of the preferred. By measuring the O2 uptake and work done with each hop, students calculate mechanical efficiency. Lessons learned from this laboratory include 1) that the metabolic cost per hop at half of the preferred frequency is nearly double the cost at the preferred frequency; 2) that when a person is forced to hop at half of their preferred frequency, the mechanical efficiency is nearly that predicted for muscle but is much higher at the preferred frequency; 3) that the preferred hop frequency is strongly body size dependent; and 4) that the hop frequency of a human is nearly identical to the galloping frequency predicted for a quadruped of our size. Together, these exercises demonstrate that humans store and recover elastic recoil potential energy when hopping but that energetic savings are highly frequency dependent. This stride frequency is dependent on body size such that frequency is likely chosen to maximize this function. Finally, by requiring students to make quantitative solutions using appropriate units and dimensions of the physical variables, these exercises sharpen analytic and quantitative skills.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Minetti, Alberto E., Paolo Gaudino, Elena Seminati y Dario Cazzola. "The cost of transport of human running is not affected, as in walking, by wide acceleration/deceleration cycles". Journal of Applied Physiology 114, n.º 4 (15 de febrero de 2013): 498–503. http://dx.doi.org/10.1152/japplphysiol.00959.2012.

Texto completo

Resumen

Although most of the literature on locomotion energetics and biomechanics is about constant-speed experiments, humans and animals tend to move at variable speeds in their daily life. This study addresses the following questions: 1) how much extra metabolic energy is associated with traveling a unit distance by adopting acceleration/deceleration cycles in walking and running, with respect to constant speed, and 2) how can biomechanics explain those metabolic findings. Ten males and ten females walked and ran at fluctuating speeds (5 ± 0, ± 1, ± 1.5, ± 2, ± 2.5 km/h for treadmill walking, 11 ± 0, ± 1, ± 2, ± 3, ± 4 km/h for treadmill and field running) in cycles lasting 6 s. Field experiments, consisting of subjects following a laser spot projected from a computer-controlled astronomic telescope, were necessary to check the noninertial bias of the oscillating-speed treadmill. Metabolic cost of transport was found to be almost constant at all speed oscillations for running and up to ±2 km/h for walking, with no remarkable differences between laboratory and field results. The substantial constancy of the metabolic cost is not explained by the predicted cost of pure acceleration/deceleration. As for walking, results from speed-oscillation running suggest that the inherent within-stride, elastic energy-free accelerations/decelerations when moving at constant speed work as a mechanical buffer for among-stride speed fluctuations, with no extra metabolic cost. Also, a recent theory about the analogy between sprint (level) running and constant-speed running on gradients, together with the mechanical determinants of gradient locomotion, helps to interpret the present findings.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Pyne, David B. y Rick L. Sharp. "Physical and Energy Requirements of Competitive Swimming Events". International Journal of Sport Nutrition and Exercise Metabolism 24, n.º 4 (agosto de 2014): 351–59. http://dx.doi.org/10.1123/ijsnem.2014-0047.

Texto completo

Resumen

The aquatic sports competitions held during the summer Olympic Games include diving, open-water swimming, pool swimming, synchronized swimming, and water polo. Elite-level performance in each of these sports requires rigorous training and practice to develop the appropriate physiological, biomechanical, artistic, and strategic capabilities specific to each sport. Consequently, the daily training plans of these athletes are quite varied both between and within the sports. Common to all aquatic athletes, however, is that daily training and preparation consumes several hours and involves frequent periods of high-intensity exertion. Nutritional support for this high-level training is a critical element of the preparation of these athletes to ensure the energy and nutrient demands of the training and competition are met. In this article, we introduce the fundamental physical requirements of these sports and specifically explore the energetics of human locomotion in water. Subsequent articles in this issue explore the specific nutritional requirements of each aquatic sport. We hope that such exploration will provide a foundation for future investigation of the roles of optimal nutrition in optimizing performance in the aquatic sports.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Kram, Rodger y Terence J. Dawson. "Energetics and biomechanics of locomotion by red kangaroos (Macropus rufus)". Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 120, n.º 1 (mayo de 1998): 41–49. http://dx.doi.org/10.1016/s0305-0491(98)00022-4.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Masumoto, Kenji y John A. Mercer. "Biomechanics of Human Locomotion in Water". Exercise and Sport Sciences Reviews 36, n.º 3 (julio de 2008): 160–69. http://dx.doi.org/10.1097/jes.0b013e31817bfe73.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

D'Août, Kristiaan. "The biomechanics of human locomotion: evolving barefoot". Footwear Science 5, sup1 (junio de 2013): S2—S3. http://dx.doi.org/10.1080/19424280.2013.797929.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Lejeune, T. M., P. A. Willems y N. C. Heglund. "Mechanics and energetics of human locomotion on sand." Journal of Experimental Biology 201, n.º 13 (1 de julio de 1998): 2071–80. http://dx.doi.org/10.1242/jeb.201.13.2071.

Texto completo

Resumen

Moving about in nature often involves walking or running on a soft yielding substratum such as sand, which has a profound effect on the mechanics and energetics of locomotion. Force platform and cinematographic analyses were used to determine the mechanical work performed by human subjects during walking and running on sand and on a hard surface. Oxygen consumption was used to determine the energetic cost of walking and running under the same conditions. Walking on sand requires 1.6-2.5 times more mechanical work than does walking on a hard surface at the same speed. In contrast, running on sand requires only 1.15 times more mechanical work than does running on a hard surface at the same speed. Walking on sand requires 2.1-2.7 times more energy expenditure than does walking on a hard surface at the same speed; while running on sand requires 1.6 times more energy expenditure than does running on a hard surface. The increase in energy cost is due primarily to two effects: the mechanical work done on the sand, and a decrease in the efficiency of positive work done by the muscles and tendons.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Wall-Scheffler, Cara M. "Energetics, Locomotion, and Female Reproduction: Implications for Human Evolution". Annual Review of Anthropology 41, n.º 1 (21 de octubre de 2012): 71–85. http://dx.doi.org/10.1146/annurev-anthro-092611-145739.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Zhang, Xiao Dong, Jian Qiao Li, Han Huang y Meng Zou. "Mechanics of Locomotion Energetics in Chinese Mitten Crab Eriocheir sinensis Milne-Edwards". Applied Mechanics and Materials 461 (noviembre de 2013): 247–53. http://dx.doi.org/10.4028/www.scientific.net/amm.461.247.

Texto completo

Resumen

The study on the locomotion mechanism in laboratory has defined performance limits for animals presently. But it is more significant for investigating mechanics of animals in their free state. In order to study the locomotion properties of Chinese mitten crabs Eriocheir sinensis Milne-Edwards on one flat terrain and four kinds of rough terrains, a high speed 3-D video recording system was used to record motion video images of crabs. The gait pattern, average speeds, the mechanical energy of the mass center and percentage energy recovery were investigated with motion analysis system. The results showed that Chinese mitten crabs used alternating tetrapod gait on flat terrain and with increasing of terrain roughness, the regularity of gait tend to be less conspicuous. Crabs used two fundamental models of energy exchanging patterns: the inverted pendulum gait and the bouncing gait and the bouncing gait was the main energy saving and conserving pattern. Keywords-biomechanics, Chinese mitten crab, rough terrain, gait, mechanical energy, percentage energy recovery

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Kaneko, Masahiro. "Energetics of human locomotion with special reference to mechanical efficiency". Taiikugaku kenkyu (Japan Journal of Physical Education, Health and Sport Sciences) 42, n.º 4 (1997): 298–305. http://dx.doi.org/10.5432/jjpehss.kj00003391593.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Sargent, A. J., D. J. E. Groom y A. Rico-Guevara. "Locomotion and Energetics of Divergent Foraging Strategies in Hummingbirds: A Review". Integrative and Comparative Biology 61, n.º 2 (10 de junio de 2021): 736–48. http://dx.doi.org/10.1093/icb/icab124.

Texto completo

Resumen

Synopsis Hummingbirds have two main foraging strategies: territoriality (defending a patch of flowers) and traplining (foraging over routine circuits of isolated patches). Species are often classified as employing one or the other. Not only have these strategies been inconsistently defined within the behavioral literature, but this simple framework also neglects the substantial evidence for flexible foraging behavior displayed by hummingbirds. Despite these limitations, research on hummingbird foraging has explored the distinct avenues of selection that proponents of either strategy presumably face: trapliners maximizing foraging efficiency, and territorialists favoring speed and maneuverability for resource defense. In earlier studies, these functions were primarily examined through wing disc loading (ratio of body weight to the circular area swept out by the wings, WDL) and predicted hovering costs, with trapliners expected to exhibit lower WDL than territorialists and thus lower hovering costs. While these pioneering models continue to play a role in current research, early studies were constrained by modest technology, and the original expectations regarding WDL have not held up when applied across complex hummingbird assemblages. Current technological advances have allowed for innovative research on the biomechanics/energetics of hummingbird flight, such as allometric scaling relationships (e.g., wing area–flight performance) and the link between high burst lifting performance and territoriality. Providing a predictive framework based on these relationships will allow us to reexamine previous hypotheses, and explore the biomechanical trade-offs to different foraging strategies, which may yield divergent routes of selection for quintessential territoriality and traplining. With a biomechanical and morphofunctional lens, here we examine the locomotor and energetic facets that dictate hummingbird foraging, and provide (a) predictions regarding the behavioral, biomechanical, and morphofunctional associations with territoriality and traplining; and (b) proposed methods of testing them. By pursuing these knowledge gaps, future research could use a variety of traits to help clarify the operational definitions of territoriality and traplining, to better apply them in the field.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Askew, Graham N., Federico Formenti y Alberto E. Minetti. "Limitations imposed by wearing armour on Medieval soldiers' locomotor performance". Proceedings of the Royal Society B: Biological Sciences 279, n.º 1729 (20 de julio de 2011): 640–44. http://dx.doi.org/10.1098/rspb.2011.0816.

Texto completo

Resumen

In Medieval Europe, soldiers wore steel plate armour for protection during warfare. Armour design reflected a trade-off between protection and mobility it offered the wearer. By the fifteenth century, a typical suit of field armour weighed between 30 and 50 kg and was distributed over the entire body. How much wearing armour affected Medieval soldiers' locomotor energetics and biomechanics is unknown. We investigated the mechanics and the energetic cost of locomotion in armour, and determined the effects on physical performance. We found that the net cost of locomotion ( C met ) during armoured walking and running is much more energetically expensive than unloaded locomotion. C met for locomotion in armour was 2.1–2.3 times higher for walking, and 1.9 times higher for running when compared with C met for unloaded locomotion at the same speed. An important component of the increased energy use results from the extra force that must be generated to support the additional mass. However, the energetic cost of locomotion in armour was also much higher than equivalent trunk loading. This additional cost is mostly explained by the increased energy required to swing the limbs and impaired breathing. Our findings can predict age-associated decline in Medieval soldiers' physical performance, and have potential implications in understanding the outcomes of past European military battles.

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Glasheen, J. W. y T. A. McMahon. "Arms are different from legs: mechanics and energetics of human hand-running". Journal of Applied Physiology 78, n.º 4 (1 de abril de 1995): 1280–87. http://dx.doi.org/10.1152/jappl.1995.78.4.1280.

Texto completo

Resumen

To determine whether nonlocomotor limbs (arms) differ from locomotor limbs (legs), we trained human subjects to run on their hands while supporting a fraction of their body weight. We wanted to know whether the low cost of force production and the speed-independent limb stiffness of locomotor limbs were characteristics associated with locomotion or were inherent properties of all limbs. We found that the limb stiffness of the human arm increases by 135% over less than a fourfold range in peak vertical force. In contrast, human legs and a variety of other mammalian locomotor limbs maintain a constant stiffness, regardless of speed and loading, for normal running. In addition, we explored the energetics of locomotion in hand-running. The economy of force generation (in J/N) is invariant with speed, as is found in legged locomotion. However, our results show that the metabolic cost of force generation while running on human arms is four to five times greater than the cost of force generation for the locomotor limbs of running quadrupeds.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Bertomeu-Motos, Arturo. "Biomechanics of human walking and stability descriptive parameters". Revista Doctorado UMH 2, n.º 1 (16 de marzo de 2016): 4. http://dx.doi.org/10.21134/doctumh.v1i1.880.

Texto completo

Resumen

From the time of Aristotle onward, there have been countless books written on the topic of movement in animals and humans. However, research of human motion, especially walking mechanisms, has increased over the last fifty years. The study of human body movement and its stability during locomotion involves both neuronal and mechanical aspect. The mechanical aspect, which is in the scope of this thesis, requires knowledge in the field of biomechanics. Walking is the most common maneuver of displacement for humans and it is performed by a stable dynamic motion. In this article it is introduced the bases of the human walking in biomechanical terms. Furthermore, two stability descriptive parameters during walking are also explained - Center of Pressure (CoP) and Zero-Moment Pint (ZMP).

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Donelan, J. M. y R. Kram. "The effect of reduced gravity on the kinematics of human walking: a test of the dynamic similarity hypothesis for locomotion." Journal of Experimental Biology 200, n.º 24 (1 de diciembre de 1997): 3193–201. http://dx.doi.org/10.1242/jeb.200.24.3193.

Texto completo

Resumen

To gain insight into the basic principles that govern the biomechanics of locomotion, we investigated the effect of reduced gravity on walking kinematics. We hypothesized that humans walk in a dynamically similar fashion at combinations of speed and simulated gravity that provide equal values of the Froude number, v2/gLleg, where v is forward speed, g is gravitational acceleration and Lleg is leg length. The Froude number has been used to predict the kinematics and kinetics of legged locomotion over a wide range of animal sizes and speeds, and thus provides a potentially unifying theory for the combined effects of speed, size and gravity on locomotion biomechanics. The occurrence of dynamic similarity at equal Froude numbers has been attributed previously to the importance of gravitational forces in determining locomotion mechanics. We simulated reduced gravity using a device that applies a nearly constant upward force to the torso while subjects walked on a treadmill. We found that at equal Froude numbers, under different levels of gravity (0.25g-1.0g), the subjects walked with nearly the same duty factor (ratio of contact time to stride time), but with relative stride lengths (Ls/Lleg, where Ls is stride length) that differed by as much as 67 %, resulting in the rejection of our hypothesis. To understand the separate effects of speed and gravity further, we compared the mechanics of walking at the same absolute speed at different levels of gravity (0.25g-1.0g). In lower gravity, subjects walked with lower duty factors (10 %) and shorter relative stride lengths (16 %). These modest changes in response to the fourfold change in gravity indicate that factors other than gravitational forces are the primary determinants of walking biomechanics.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Ewart, Heather, Peter Tickle, Robert Nudds, William Sellers, Dane Crossley y Jonathan Codd. "Mediterranean Spur-Thighed Tortoises (Testudo graeca) Have Optimal Speeds at Which They Can Minimise the Metabolic Cost of Transport, on a Treadmill". Biology 11, n.º 7 (13 de julio de 2022): 1052. http://dx.doi.org/10.3390/biology11071052.

Texto completo

Resumen

Tortoises are famed for their slow locomotion, which is in part related to their herbivorous diet and the constraints imposed by their protective shells. For most animals, the metabolic cost of transport (CoT) is close to the value predicted for their body mass. Testudines appear to be an exception to this rule, as previous studies indicate that, for their body mass, they are economical walkers. The metabolic efficiency of their terrestrial locomotion is explainable by their walking gait biomechanics and the specialisation of their limb muscle physiology, which embodies a predominance of energy-efficient slow-twitch type I muscle fibres. However, there are only two published experimental reports of the energetics of locomotion in tortoises, and these data show high variability. Here, Mediterranean spur-thighed tortoises (Testudo graeca) were trained to walk on a treadmill. Open-flow respirometry and high-speed filming were simultaneously used to measure the metabolic cost of transport and to quantify limb kinematics, respectively. Our data support the low cost of transport previously reported and demonstrate a novel curvilinear relationship to speed in Testudines, suggesting tortoises have an energetically optimal speed range over which they can move in order to minimise the metabolic cost of transport.

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Formenti, F. y A. E. Minetti. "Human locomotion on ice: the evolution of ice-skating energetics through history". Journal of Experimental Biology 210, n.º 10 (15 de mayo de 2007): 1825–33. http://dx.doi.org/10.1242/jeb.002162.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Martelli, Dario, Federica Vannetti, Mario Cortese, Peppino Tropea, Francesco Giovacchini, Silvestro Micera, Vito Monaco y Nicola Vitiello. "The effects on biomechanics of walking and balance recovery in a novel pelvis exoskeleton during zero-torque control". Robotica 32, n.º 8 (20 de junio de 2014): 1317–30. http://dx.doi.org/10.1017/s0263574714001568.

Texto completo

Resumen

SUMMARYFall-related accidents are among the most serious concerns in elderly people, amputees and subjects with neurological disorders. The aim of this paper was to investigate the behaviour of healthy subjects wearing a novel light-weight pelvis exoskeleton controlled in zero-torque mode while carrying out unperturbed locomotion and managing unexpected perturbations. Results showed that the proposed exoskeleton was unobtrusive and had a minimum loading effect on the human biomechanics during unperturbed locomotion. Conversely, it affected the movement of the trailing leg while subjects managed unexpected slipping-like perturbations. These findings support further investigations on the potential use of powered exoskeletons to assist locomotion and, possibly prevent incipient falls.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Zernicke, Ronald F., Grant C. Goulet, Peter R. Cavanagh, Benno M. Nigg, James A. Ashton-Miller, Heather A. McKay y Ton van den Bogert. "Impact of Biomechanics Research on Society". Kinesiology Review 1, n.º 1 (febrero de 2012): 5–16. http://dx.doi.org/10.1123/krj.1.1.5.

Texto completo

Resumen

As a field, biomechanics comprises research from the molecular and cellular levels, to tissues, to organs, to organisms and their movements. In the past 50 years, the impact of biomechanics research on society has been amplified dramatically. Here, we provide five brief summaries of exemplar biomechanics results that have had substantial impact on health and our society, namely 1) spaceflight and microgravitational effects on musculoskeletal health; 2) impact forces, soft tissue vibrations, and skeletal muscle tuning affecting human locomotion; 3) childbirth mechanics, injuries, and pelvic floor dysfunction; 4) prescriptive physical activity in childhood to enhance skeletal growth and development to prevent osteoporotic fractures in adulthood and aging; and 5) creative innovations in technology that have transformed the visual arts and entertainment.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Skvortsov, Dmitry, Victor Anisimov y Alina Aizenshtein. "Experimental Study of Military Crawl as a Special Type of Human Quadripedal Automatic Locomotion". Applied Sciences 11, n.º 16 (20 de agosto de 2021): 7666. http://dx.doi.org/10.3390/app11167666.

Texto completo

Resumen

The biomechanics of military crawl locomotion is poorly covered in scientific literature so far. Crawl locomotion may be used as a testing procedure which allows for the detection of not only obvious, but also hidden locomotor dysfunctions. The aim of the study was to investigate the biomechanics of crawling among healthy adult participants. Eight healthy adults aged 15–31 (four women and four men) were examined by means of a 3D kinematic analysis with Optitrack optical motion-capture system which consists of 12 Flex 13 cameras. The movements of the shoulder, elbow, knee, and hip joints were recorded. A person was asked to crawl 4 m on his/her belly. The obtained results including space-time data let us characterize military crawling in terms of pelvic and lower limb motions as a movement similar to walking but at a more primitive level. Progressive and propulsive motions are characterized as normal; additional right–left side motions—with high degree of reciprocity. It was found that variability of the left-side motions is significantly lower than that of the right side (Z = 4.49, p < 0.0001). The given normative data may be used as a standard to estimate the test results for patients with various pathologies of motor control (ataxia, abasia, etc.).

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Derby, Hunter, Harish Chander, Sachini N. K. Kodithuwakku Arachchige, Alana J. Turner, Adam C. Knight, Reuben Burch, Charles Freeman, Chip Wade y John C. Garner. "Occupational Footwear Design Influences Biomechanics and Physiology of Human Postural Control and Fall Risk". Applied Sciences 13, n.º 1 (22 de diciembre de 2022): 116. http://dx.doi.org/10.3390/app13010116.

Texto completo

Resumen

While design modifications present on work boots improve safety, they may not always provide optimal human performance during work tasks. Understanding the impact of these different design features on biomechanical and physiological postural control and locomotion variables can aid in better design modifications that can provide a safe and efficient human performance. This brief review focuses on a series of studies conducted by the current research team, that have tested three different work boots (SB: high-top steel-toed work boots; TB: high-top tactical work boots; SR: low-top slip-resistant work boots). The series of studies included testing of these work boots or combinations of them under acute and chronic simulated occupational workloads, assessing biomechanical variable such as postural stability, gait, slips, and muscle activity, as well as physiological variables such as heart rate, energy expenditure, oxygen consumption, and pain perception. The impact of each of the work boots and their design feature on postural control and locomotion are summarized from these studies’ previously published literature. Finally, work boot design suggestions for optimal human performance are provided for better work boot selection, modification, and design.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Farris, Dominic James y Gregory S. Sawicki. "The mechanics and energetics of human walking and running: a joint level perspective". Journal of The Royal Society Interface 9, n.º 66 (25 de mayo de 2011): 110–18. http://dx.doi.org/10.1098/rsif.2011.0182.

Texto completo

Resumen

Humans walk and run at a range of speeds. While steady locomotion at a given speed requires no net mechanical work, moving faster does demand both more positive and negative mechanical work per stride. Is this increased demand met by increasing power output at all lower limb joints or just some of them? Does running rely on different joints for power output than walking? How does this contribute to the metabolic cost of locomotion? This study examined the effects of walking and running speed on lower limb joint mechanics and metabolic cost of transport in humans. Kinematic and kinetic data for 10 participants were collected for a range of walking (0.75, 1.25, 1.75, 2.0 m s −1 ) and running (2.0, 2.25, 2.75, 3.25 m s −1 ) speeds. Net metabolic power was measured by indirect calorimetry. Within each gait, there was no difference in the proportion of power contributed by each joint (hip, knee, ankle) to total power across speeds. Changing from walking to running resulted in a significant ( p = 0.02) shift in power production from the hip to the ankle which may explain the higher efficiency of running at speeds above 2.0 m s −1 and shed light on a potential mechanism behind the walk–run transition.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Banga, Harish Kumar, R. M. Belokar, Sandip Dhole, Parveen Kalra y Rajesh Kumar. "Three Dimensional Gait Assessment During Walking of Healthy People and Drop Foot Patients". Defence Life Science Journal 2, n.º 1 (29 de marzo de 2017): 14. http://dx.doi.org/10.14429/dlsj.2.10395.

Texto completo

Resumen

The aim of the present study is to clinical gait analysis of normal human and drop foot patients. Gait analysis is the systematic study of <a title="Animal locomotion" href="https://en.wikipedia.org/wiki/Animal_locomotion">animal locomotion</a>, more specifically the study of human motion, using the eye and the brain of observers, augmented by <a title="Instrumentation" href="https://en.wikipedia.org/wiki/Instrumentation">instrumentation</a> for measuring body movements, <a title="Biomechanics" href="https://en.wikipedia.org/wiki/Biomechanics">body mechanics</a>, and the activity of the muscles. Gait analysis is used to assess, plan, and treat individuals with conditions affecting their ability to walk. Foot drop is a deceptively simple name for a potentially complex problem. It can be defined as a significant weakness of ankle and toe dorsiflexion. The foot and ankle dorsiflexors include the tibialis anterior, the extensor hallucis longus (EHL), and the extensor digitorum longus (EDL). These muscles help the body clear the foot during the swing phase and control plantar flexion of the foot at heel strike

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Wade, Chip y Mark S. Redfern. "Ground Reaction Forces during Human Locomotion on Railroad Ballast". Journal of Applied Biomechanics 23, n.º 4 (noviembre de 2007): 322–29. http://dx.doi.org/10.1123/jab.23.4.322.

Texto completo

Resumen

Locomotion over ballast surfaces provides a unique situation for investigating the biomechanics of gait. Although much research has focused on level and sloped walking on a smooth, firm surface in order to understand the common kinematic and kinetic variables associated with human locomotion, the literature currently provides few if any discussions regarding the dynamics of locomotion on surfaces that are either rocky or uneven. The purpose of this study was to investigate a method for using force plates to measure the ground reaction forces (GRFs) during gait on ballast. Ballast is a construction aggregate of unsymmetrical rock used in industry for the purpose of forming track bed on which railway ties are laid or in yards where railroad cars are stored. It is used to facilitate the drainage of water and to create even running surfaces. To construct the experimental ballast surfaces, 31.75-mm (1¼-in.) marble ballast at depths of approximately 63.5 mm (2.5 in.) or 101.6 mm (4 in.) were spread over a carpeted vinyl tile walkway specially designed for gait studies. GRF magnitudes and time histories from a force plate were collected under normal smooth surface and under both ballast surface conditions for five subjects. GRF magnitudes and time histories during smooth surface walking were similar to GRF magnitudes and time histories from the two ballast surface conditions. The data presented here demonstrate the feasibility of using a force plate system to expand the scope of biomechanical analyses of locomotion on ballast surfaces.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Baritz, Mihaela Ioana y Diana Laura Cotoros. "Oscillatory Movements Analysis at Knee Level". Applied Mechanics and Materials 436 (octubre de 2013): 271–76. http://dx.doi.org/10.4028/www.scientific.net/amm.436.271.

Texto completo

Resumen

Some theoretical and experimental considerations upon the biomechanics of oscillatory flexion-extension movements developed at knee level of human subjects, without previous detected pathologies are presented in this paper. Thus, the first part of the paper is referring to the analysis of aspects related to the locomotion system biomechanics concerning the flexion-extension movement at knee level and also to the setting of various samples of subjects out of which the examples for the proposed methodology application will be selected. In the second part of the paper, the analysis structures required for the recording and assessment of oscillatory movements biomechanics at knee level are developed and presented. In the third part, the results and conclusions regarding the behavior and performance limits of movements at knee level are presented and processed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Leitner, Christoph, Pascal A. Hager, Harald Penasso, Markus Tilp, Luca Benini, Christian Peham y Christian Baumgartner. "Ultrasound as a Tool to Study Muscle–Tendon Functions during Locomotion: A Systematic Review of Applications". Sensors 19, n.º 19 (5 de octubre de 2019): 4316. http://dx.doi.org/10.3390/s19194316.

Texto completo

Resumen

Movement science investigating muscle and tendon functions during locomotion utilizes commercial ultrasound imagers built for medical applications. These limit biomechanics research due to their form factor, range of view, and spatio-temporal resolution. This review systematically investigates the technical aspects of applying ultrasound as a research tool to investigate human and animal locomotion. It provides an overview on the ultrasound systems used and of their operating parameters. We present measured fascicle velocities and discuss the results with respect to operating frame rates during recording. Furthermore, we derive why muscle and tendon functions should be recorded with a frame rate of at least 150 Hz and a range of view of 250 mm. Moreover, we analyze why and how the development of better ultrasound observation devices at the hierarchical level of muscles and tendons can support biomechanics research. Additionally, we present recent technological advances and their possible application. We provide a list of recommendations for the development of a more advanced ultrasound sensor system class targeting biomechanical applications. Looking to the future, mobile, ultrafast ultrasound hardware technologies create immense opportunities to expand the existing knowledge of human and animal movement.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Baritz, Mihaela Ioana, Laura Diana Cotoros, Ileana Ciobanu y Raluca Muntean. "Forces Distribution Analysis Developed in the Plantar Surface in Simulation Case of Controlled Blocking of Joints". Applied Mechanics and Materials 656 (octubre de 2014): 642–49. http://dx.doi.org/10.4028/www.scientific.net/amm.656.642.

Texto completo

Resumen

Some theoretical and experimental considerations upon the biomechanics of the movements developed at foot level of human subjects without previous detected pathologies are presented in this paper. Thus, the first part of the paper is referring to the analysis of aspects related to the biomechanics of the locomotion system, aspects concerning the forces distribution at plantar surface level and also concerning the setting of various samples of subjects out of which the examples for the proposed methodology application will be selected. In the second part of the paper, the analysis structures required for the recording and assessment of simulation cases with blocked joints movements’ biomechanics at knee and ankle level are developed and presented. In the third part, the results and conclusions regarding the behavior and performance limits of forces and pressures at plantar surface level are presented and processed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Jovanovic, Kosta, Jovana Vranic y Nadica Miljkovic. "Hill’s and Huxley’s muscle models - tools for simulations in biomechanics". Serbian Journal of Electrical Engineering 12, n.º 1 (2015): 53–67. http://dx.doi.org/10.2298/sjee1501053j.

Texto completo

Resumen

Numerous mathematical models of human skeletal muscles have been developed. However, none of them is adopted as a general one and each of them is suggested for some specific purpose. This topic is essential in humanoid robotics, since we firstly need to understand how human moves and acts in order to exploit human movement patterns in robotics and design human like actuators. Simulations in biomechanics are intensively used in research of locomotion, safe human-robot interaction, development of novel robotic actuators, biologically inspired control algorithms, etc. This paper presents two widely adopted muscle models (Hill?s and Huxley?s model), elaborates their features and demonstrates trade-off between their accuracy and efficiency of computer simulations. The simulation setup contains mathematical representation of passive muscle structures as well as mathematical model of an elastic tendon as a series elastic actuation element. Advanced robot control techniques point out energy consumption as one of the key issues. Therefore, energy store and release mechanism in elastic elements in both tendon and muscle, based on the simulation models, are considered.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

‘Knoek’ van Soest, A. J., D. A. Kistemaker, M. F. Bobbert y K. K. Lemaire. "The theory on ‘gravity-driven horizontal locomotion’ is flawed; a commentary on ‘Gravity-driven horizontal locomotion: theory and experiment’ by Kanstad & Kononoff (2015)". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 473, n.º 2197 (enero de 2017): 20160683. http://dx.doi.org/10.1098/rspa.2016.0683.

Texto completo

Resumen

In a recent paper, Kanstad & Kononoff ( Proc. R. Soc. A 471 , 20150287. ( doi:10.1098/rspa.2015.0287 )) presented a theoretical analysis of the mechanical energetics of a particular style of human walking and running. According to their analysis, the force of gravity provides energy when this style of horizontal walking/running is adopted. Furthermore, Kanstad & Kononoff suggested that uphill walking at zero energy cost is possible when the suggested style of walking is adopted. In this commentary, we argue that these claims violate the basic laws of thermodynamics, and are based on erroneous application of the basic laws of classical mechanics.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Watson, Rebecca R., Jonas Rubenson, Lisa Coder, Donald F. Hoyt, Matthew W. G. Propert y Richard L. Marsh. "Gait-specific energetics contributes to economical walking and running in emus and ostriches". Proceedings of the Royal Society B: Biological Sciences 278, n.º 1714 (diciembre de 2010): 2040–46. http://dx.doi.org/10.1098/rspb.2010.2022.

Texto completo

Resumen

A widely held assumption is that metabolic rate ( Ė met ) during legged locomotion is linked to the mechanics of different gaits and this linkage helps explain the preferred speeds of animals in nature. However, despite several prominent exceptions, Ė met of walking and running vertebrates has been nearly uniformly characterized as increasing linearly with speed across all gaits. This description of locomotor energetics does not predict energetically optimal speeds for minimal cost of transport ( E cot ). We tested whether large bipedal ratite birds (emus and ostriches) have gait-specific energetics during walking and running similar to those found in humans. We found that during locomotion, emus showed a curvilinear relationship between Ė met and speed during walking, and both emus and ostriches demonstrated an abrupt change in the slope of Ė met versus speed at the gait transition with a linear increase during running. Similar to human locomotion, the minimum net E cot calculated after subtracting resting metabolism was lower in walking than in running in both species. However, the difference in net E cot between walking and running was less than is found in humans because of a greater change in the slope of Ė met versus speed at the gait transition, which lowers the cost of running for the avian bipeds. For emus, we also show that animals moving freely overground avoid a range of speeds surrounding the gait-transition speed within which the E cot is large. These data suggest that deviations from a linear relation of metabolic rate and speed and variations in transport costs with speed are more widespread than is often assumed, and provide new evidence that locomotor energetics influences the choice of speed in bipedal animals. The low cost of transport for walking is probably ecologically important for emus and ostriches because they spend the majority of their active day walking, and thus the energy used for locomotion is a large part of their daily energy budget.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Terrier, Philippe, Quentin Ladetto, Bertrand Merminod y Yves Schutz. "High-precision satellite positioning system as a new tool to study the biomechanics of human locomotion". Journal of Biomechanics 33, n.º 12 (diciembre de 2000): 1717–22. http://dx.doi.org/10.1016/s0021-9290(00)00133-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Ivanenko, Y. P., A. d'Avella, R. E. Poppele y F. Lacquaniti. "On the Origin of Planar Covariation of Elevation Angles During Human Locomotion". Journal of Neurophysiology 99, n.º 4 (abril de 2008): 1890–98. http://dx.doi.org/10.1152/jn.01308.2007.

Texto completo

Resumen

Leg segment rotations in human walking covary, so that the three-dimensional trajectory of temporal changes in the elevation angles lies close to a plane. Recently the role of central versus biomechanical constraints on the kinematics control of human locomotion has been questioned. Here we show, based on both modeling and experimental data, that the planar law of intersegmental coordination is not a simple consequence of biomechanics. First, the full limb behavior in various locomotion modes (walking on inclined surface, staircase stepping, air-stepping, crouched walking, hopping) can be expressed as 2 degrees of freedom planar motion even though the orientation of the plane and pairwise segment angle correlations may differ substantially. Second, planar covariation is not an inevitable outcome of any locomotor movement. It can be systematically violated in some conditions (e.g., when stooping and grasping an object on the floor during walking or in toddlers at the onset of independent walking) or transferred into a simple linear relationship in others (e.g., during stepping in place). Finally, all three major limb segments contribute importantly to planar covariation and its characteristics resulting in a certain endpoint trajectory defined by the limb axis length and orientation. Recent advances in the neural control of movement support the hypothesis about central representation of kinematics components.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

RADKHAH, KATAYON, CHRISTOPHE MAUFROY, MORITZ MAUS, DORIAN SCHOLZ, ANDRE SEYFARTH y OSKAR VON STRYK. "CONCEPT AND DESIGN OF THE BIOBIPED1 ROBOT FOR HUMAN-LIKE WALKING AND RUNNING". International Journal of Humanoid Robotics 08, n.º 03 (septiembre de 2011): 439–58. http://dx.doi.org/10.1142/s0219843611002587.

Texto completo

Resumen

Biomechanics research shows that the ability of the human locomotor system depends on the functionality of a highly compliant motor system that enables a variety of different motions (such as walking and running) and control paradigms (such as flexible combination of feedforward and feedback controls strategies) and reliance on stabilizing properties of compliant gaits. As a new approach of transferring this knowledge into a humanoid robot, the design and implementation of the first of a planned series of biologically inspired, compliant, and musculoskeletal robots is presented in this paper. Its three-segmented legs are actuated by compliant mono- and biarticular structures, which mimic the main nine human leg muscle groups, by applying series elastic actuation consisting of cables and springs in combination with electrical actuators. By means of this platform, we aim to transfer versatile human locomotion abilities, namely running and later on walking, into one humanoid robot design. First experimental results for passive rebound, as well as push-off with active knee and ankle joints, and synchronous and alternate hopping are described and discussed. BioBiped1 will serve for further evaluation of the validity of biomechanical concepts for humanoid locomotion.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Raspudić, Vesna. "Computer Simulation of Lower Extremities Movement during Stair Climbing". Applied Mechanics and Materials 330 (junio de 2013): 407–11. http://dx.doi.org/10.4028/www.scientific.net/amm.330.407.

Texto completo

Resumen

Tracking of human body motion is applied in many fields, such as virtual reality, clinical biomechanics, the study of man-machine-environment relationship, the analysis of sports movements, etc. Nowadays, the preferred approach to tracking human body motion is based on the use of appropriate optical or magnetic markers, which are placed on specific landmark points, and real-time estimating of their spatial coordinates. With the improvements introduced in computerized monitoring of human motion kinematics, it is important to emphasize the significance of combining motion capture data with commercial CAD packages. The aim of this research was to develop new interactive methods in creating virtual models within the highly sophisticated CAD computer technologies, as well as computer simulations for analyzing the various forms of human locomotion. Within this research, special attention is focused on the study of locomotion when climbing stairs, as an activity that requires large amount of metabolic energy, and thus represents great difficulty in performing daily activities for people with disorders of the musculoskeletal system, and particularly for people with lower limb amputation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Cappellini, Germana, Yuri P. Ivanenko, Nadia Dominici, Richard E. Poppele y Francesco Lacquaniti. "Migration of Motor Pool Activity in the Spinal Cord Reflects Body Mechanics in Human Locomotion". Journal of Neurophysiology 104, n.º 6 (diciembre de 2010): 3064–73. http://dx.doi.org/10.1152/jn.00318.2010.

Texto completo

Resumen

During the evolution of bipedal modes of locomotion, a sequential rostrocaudal activation of trunk muscles due to the undulatory body movements was replaced by more complex and discrete bursts of activity. Nevertheless, the capacity for segmental rhythmogenesis and the rostrocaudal propagation of spinal cord activity has been conserved. In humans, motoneurons of different muscles are arranged in columns, with a specific grouping of muscles at any given segmental level. The muscle patterns of locomotor activity and the biomechanics of the body center of mass have been studied extensively, but their interrelationship remains poorly understood. Here we mapped the electromyographic activity recorded from 30 bilateral leg muscles onto the spinal cord in approximate rostrocaudal locations of the motoneuron pools during walking and running in humans. We found that the rostrocaudal displacements of the center of bilateral motoneuron activity mirrored the changes in the energy due to the center-of-body mass motion. The results suggest that biomechanical mechanisms of locomotion, such as the inverted pendulum in walking and the pogo-stick bouncing in running, may be tightly correlated with specific modes of progression of motor pool activity rostrocaudally in the spinal cord.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Kivell, Tracy L. "Evidence in hand: recent discoveries and the early evolution of human manual manipulation". Philosophical Transactions of the Royal Society B: Biological Sciences 370, n.º 1682 (19 de noviembre de 2015): 20150105. http://dx.doi.org/10.1098/rstb.2015.0105.

Texto completo

Resumen

For several decades, it was largely assumed that stone tool use and production were abilities limited to the genus Homo . However, growing palaeontological and archaeological evidence, comparative extant primate studies, as well as results from methodological advancements in biomechanics and morphological analyses, have been gradually accumulating and now provide strong support for more advanced manual manipulative abilities and tool-related behaviours in pre- Homo hominins than has been traditionally recognized. Here, I review the fossil evidence related to early hominin dexterity, including the recent discoveries of relatively complete early hominin hand skeletons, and new methodologies that are providing a more holistic interpretation of hand function, and insight into how our early ancestors may have balanced the functional requirements of both arboreal locomotion and tool-related behaviours.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Jambrešić, Gordana y Maja Paunović. "Osteometry, Variability, Biomechanics and Locomotion Pattern of the Cave Bear Limb Bones from Croatian Localities". Geologia Croatica 55, n.º 1 (2002): 1–10. http://dx.doi.org/10.4154/gc.2002.01.

Texto completo

Resumen

The estimated stylo- and zeugopodial bone index is lower for the cavebears from the mountainous region (Cerovaèke peæine caves) than thebone index from the hilly-lowlands caves (Vindija, Velika peæina,Veternica) and indicates that limb loading depends on the body massand palaeoenvironment. The type of movement was similar to thelocomotion of the recent brown bear but with somewhat moreexpressed plantigrady on the hind limbs. At the same time, the sexratio of the studied material depends firstly on the site morphology(endogene or exogene cave), i.e. its function (dense or periodicallyvisited shelter), and also on geological processes and human activity.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Blickhan, Reinhard, Andre Seyfarth, Hartmut Geyer, Sten Grimmer, Heiko Wagner y Michael Günther. "Intelligence by mechanics". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365, n.º 1850 (17 de noviembre de 2006): 199–220. http://dx.doi.org/10.1098/rsta.2006.1911.

Texto completo

Resumen

Research on the biomechanics of animal and human locomotion provides insight into basic principles of locomotion and respective implications for construction and control. Nearly elastic operation of the leg is necessary to reproduce the basic dynamics in walking and running. Elastic leg operation can be modelled with a spring-mass model. This model can be used as a template with respect to both gaits in the construction and control of legged machines. With respect to the segmented leg, the humanoid arrangement saves energy and ensures structural stability. With the quasi-elastic operation the leg inherits the property of self-stability, i.e. the ability to stabilize a system in the presence of disturbances without sensing the disturbance or its direct effects. Self-stability can be conserved in the presence of musculature with its crucial damping property. To ensure secure foothold visco-elastic suspended muscles serve as shock absorbers. Experiments with technically implemented leg models, which explore some of these principles, are promising.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Pavei, Gaspare y Alberto E. Minetti. "Hopping locomotion at different gravity: metabolism and mechanics in humans". Journal of Applied Physiology 120, n.º 10 (15 de mayo de 2016): 1223–29. http://dx.doi.org/10.1152/japplphysiol.00839.2015.

Texto completo

Resumen

Previous literature on the effects of low gravity on the mechanics and energetics of human locomotion already dealt with walking, running, and skipping. The aim of the present study is to obtain a comprehensive view on that subject by including measurements of human hopping in simulated low gravity, a gait often adopted in many Apollo Missions and documented in NASA footage. Six subjects hopped at different speeds at terrestrial, Martian, and Lunar gravity on a treadmill while oxygen consumption and 3D body kinematic were sampled. Results clearly indicate that hopping is too metabolically expensive to be a sustainable locomotion on Earth but, similarly to skipping (and running), its economy greatly (more than ×10) increases at lower gravity. On the Moon, the metabolic cost of hopping becomes even lower than that of walking, skipping, and running, but the general finding is that gaits with very different economy on Earth share almost the same economy on the Moon. The mechanical reasons for such a decrease in cost are discussed in the paper. The present data, together with previous findings, will allow also to predict the aerobic traverse range/duration of astronauts when getting far from their base station on low gravity planets.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Van Emmerik, Richard E. A., Michael T. Rosenstein, William J. McDermott y Joseph Hamill. "A Nonlinear Dynamics Approach to Human Movement". Journal of Applied Biomechanics 20, n.º 4 (noviembre de 2004): 396–420. http://dx.doi.org/10.1123/jab.20.4.396.

Texto completo

Resumen

Nonlinear dynamics and dynamical systems approaches and methodologies are increasingly being implemented in biomechanics and human movement research. Based on the early insights of Nicolai Bernstein (1967), a significantly different outlook on the movement control “problem” over the last few decades has emerged. From a focus on relatively simple movements has arisen a research focus with the primary goal to study movement in context, allowing the complexity of patterns to emerge. The approach taken is that the control of multiple degrees-of-freedom systems is not necessarily more difficult or complex than that of systems only comprising a few degrees of freedom. Complex patterns and dynamics might not require complex control structures. In this paper we present a tutorial overview of the mathematical underpinnings of nonlinear dynamics and some of its basic analysis tools. This should provide the reader with a basic level of understanding about the mathematical principles and concepts underlying pattern stability and change. This will be followed by an overview of dynamical systems approaches in the study of human movement. Finally, we discuss recent progress in the application of nonlinear dynamical techniques to the study of human locomotion, with particular focus on relative phase techniques for the assessment of coordination.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

MacLean, Mhairi K. y Daniel P. Ferris. "Human muscle activity and lower limb biomechanics of overground walking at varying levels of simulated reduced gravity and gait speeds". PLOS ONE 16, n.º 7 (14 de julio de 2021): e0253467. http://dx.doi.org/10.1371/journal.pone.0253467.

Texto completo

Resumen

Reducing the mechanical load on the human body through simulated reduced gravity can reveal important insight into locomotion biomechanics. The purpose of this study was to quantify the effects of simulated reduced gravity on muscle activation levels and lower limb biomechanics across a range of overground walking speeds. Our overall hypothesis was that muscle activation amplitudes would not decrease proportionally to gravity level. We recruited 12 participants (6 female, 6 male) to walk overground at 1.0, 0.76, 0.55, and 0.31 G for four speeds: 0.4, 0.8, 1.2, and 1.6 ms-1. We found that peak ground reaction forces, peak knee extension moment in early stance, peak hip flexion moment, and peak ankle extension moment all decreased substantially with reduced gravity. The peak knee extension moment at late stance/early swing did not change with gravity. The effect of gravity on muscle activity amplitude varied considerably with muscle and speed, often varying nonlinearly with gravity level. Quadriceps (rectus femoris, vastus lateralis, & vastus medialis) and medial gastrocnemius activity decreased in stance phase with reduced gravity. Soleus and lateral gastrocnemius activity had no statistical differences with gravity level. Tibialis anterior and biceps femoris increased with simulated reduced gravity in swing and stance phase, respectively. The uncoupled relationship between simulated gravity level and muscle activity have important implications for understanding biomechanical muscle functions during human walking and for the use of bodyweight support for gait rehabilitation after injury.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Wall-Scheffler, Cara M. "Size and Shape: Morphology's Impact on Human Speed and Mobility". Journal of Anthropology 2012 (28 de agosto de 2012): 1–9. http://dx.doi.org/10.1155/2012/340493.

Texto completo

Resumen

While human sexual dimorphism is generally expected to be the result of differential reproductive strategies, it has the potential to create differences in the energetics of locomotion and the speed at which each morph travels, particularly since people have been shown to choose walking speeds around their metabolic optimum. Here, people of varying sizes walked around a track at four self-selected speeds while their metabolic rate was collected, in order to test whether the size variation within a population could significantly affect the shape of the optimal walking curve. The data show that larger people have significantly faster optimal walking speeds, higher costs at their optimal speed, and a more acute optimal walking curve (thus an increased penalty for walking at suboptimal speeds). Bigger people who also have wider bitrochanteric breadths have lower metabolic costs at their minimum than bigger people with a more narrow bitrochanteric breadth. Finally, tibia length significantly positively predicts optimal walking speed. These results suggest sex-specific walking groups typical of living human populations may be the result of energy maximizing strategies. In addition, testable hypotheses of group strategies are put forth.

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Farris, Dominic James y Gregory S. Sawicki. "Linking the mechanics and energetics of hopping with elastic ankle exoskeletons". Journal of Applied Physiology 113, n.º 12 (15 de diciembre de 2012): 1862–72. http://dx.doi.org/10.1152/japplphysiol.00802.2012.

Texto completo

Resumen

The springlike mechanics of the human leg during bouncing gaits has inspired the design of passive assistive devices that use springs to aid locomotion. The purpose of this study was to test whether a passive spring-loaded ankle exoskeleton could reduce the mechanical and energetic demands of bilateral hopping on the musculoskeletal system. Joint level kinematics and kinetics were collected with electromyographic and metabolic energy consumption data for seven participants hopping at four frequencies (2.2, 2.5, 2.8, and 3.2 Hz). Hopping was performed without an exoskeleton; with an springless exoskeleton; and with a spring-loaded exoskeleton. Spring-loaded ankle exoskeletons reduced plantar flexor muscle activity and the biological contribution to ankle joint moment (15–25%) and average positive power (20–40%). They also facilitated reductions in metabolic power (15–20%) across frequencies from 2.2 to 2.8 Hz compared with hopping with a springless exoskeleton. Reductions in metabolic power compared with hopping with no exoskeleton were restricted to hopping at 2.5 Hz only (12%). These results highlighted the importance of reducing the rate of muscular force production and work to achieve metabolic reductions. They also highlighted the importance of assisting muscles acting at the knee joint. Exoskeleton designs may need to be tuned to optimize exoskeleton mass, spring stiffness, and spring slack length to achieve greater metabolic reductions.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Shakibaee, Abolfazl, Alireza Asgari, Kamal Mostafavi, Gholamhossein Pourtaghi y Zeynab Ebrahimpour. "Simulation and dynamic analysis of military marching using lower limbs anthropometric data". Romanian Journal of Military Medicine 122, n.º 3 (1 de diciembre de 2019): 92–100. http://dx.doi.org/10.55453/rjmm.2019.122.3.13.

Texto completo

Resumen

Background: Gait analysis is receiving increasing attention due to various applications in athletic performance, man-machine interfaces and especially in military services. This analysis involves the analysis of human locomotion augmented by body movements and biomechanics of joints. The kinematic motion of the body during a gait cycle capturing by cameras is then used as the desired target for modelling the motion of body segments. By taking advantage of gait analysis concept, this study aims to model the military marching, using anthropometric data with the focus on lower limbs while introducing top candidates with better healthy conditions in lower limb joints during a cycle of marching. Methods: Using 100 anthropometric data from military soldiers, equations of motion for the model are derived by applying Lagrangian methods in an inverse dynamic approach. In this model, the joints are simulated using springs and dampers while the actuators, simulated the muscles, acted like motors and applied enough torque on joints so that the model motion replicates normal military marching. Finally, all the springs and dampers coefficients are driven from optimization process. Results: Hip, knee and ankle torques were calculated after the optimization process for all 100 soldiers and then 5 candidates among them were established with less suffering forces and torques in their joints. Conclusions: In this study using biomechanics basics and anthropometry data at the same time, a standard could be evaluated to select the soldiers based on healthy condition of lower organs. Keywords: marching, anthropometric data, gait analysis, biomechanics, torque, equations of motion, optimization.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Reghem, E., E. Pouydebat, P. Gorce y V. Bels. "A biomechanics comparison of grasping in locomotion and feeding with the mouse lemur (Microcebus murinus, Primate): a study case". Computer Methods in Biomechanics and Biomedical Engineering 13, sup1 (septiembre de 2010): 121–23. http://dx.doi.org/10.1080/10255842.2010.495593.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Han, Sang Kuy, Keonwoo Kim, Yejoon Rim, Manhyung Han, Youngjeon Lee, Sung-Hyun Park, Won Seok Choi, Keyoung Jin Chun y Dong-Seok Lee. "A Novel, Automated, and Real-Time Method for the Analysis of Non-Human Primate Behavioral Patterns Using a Depth Image Sensor". Applied Sciences 12, n.º 1 (4 de enero de 2022): 471. http://dx.doi.org/10.3390/app12010471.

Texto completo

Resumen

By virtue of their upright locomotion, similar to that of humans, motion analysis of non-human primates has been widely used in order to better understand musculoskeletal biomechanics and neuroscience problems. Given the difficulty of conducting a marker-based infrared optical tracking system for the behavior analysis of primates, a 2-dimensional (D) video analysis has been applied. Distinct from a conventional marker-based optical tracking system, a depth image sensor system provides 3-D information on movement without any skin markers. The specific aim of this study was to develop a novel algorithm to analyze the behavioral patterns of non-human primates in a home cage using a depth image sensor. The behavioral patterns of nine monkeys in their home cage, including sitting, standing, and pacing, were captured using a depth image sensor. Thereafter, these were analyzed by observers’ manual assessment and the newly written automated program. We confirmed that the measurement results from the observers’ manual assessments and the automated program with depth image analysis were statistically identical.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Živanović, Stana, Bintian Lin, Hiep Vu Dang, Sigong Zhang, Mladen Ćosić, Colin Caprani y Qingwen Zhang. "Evaluation of Inverted-Pendulum-with-Rigid-Legs Walking Locomotion Models for Civil Engineering Applications". Buildings 12, n.º 8 (11 de agosto de 2022): 1216. http://dx.doi.org/10.3390/buildings12081216.

Texto completo

Resumen

Bipedal models for walkers, originally developed in the research field of biomechanics, have been identified as potential candidates for modelling pedestrians in structural engineering applications. These models provide insight into both the kinetics and kinematics of walking locomotion and are considered to have a significant potential to improve the vibration serviceability assessment of civil engineering structures. Despite this notion, the ability of the bipedal models to represent the key features of the walking gait and natural variability within the pedestrian population are still under-researched. This paper critically evaluates the performance of two bipedal models with rigid legs to realistically both reproduce key features of an individual pedestrian’s walking gait and represent a wide range of individuals. The evaluation is performed for walking on a rigid, rather than vibrating, structure due to the availability of experimental data and expectation that successful modelling on rigid surfaces is a necessary condition for progressing towards modelling on the vibrating structures. Ready-to-use equations are provided and the ability of the models to represent the kinematics and kinetics of individual pedestrians as well as the inter-subject variability typical of the human population is critically evaluated. It was found that the two models could generate realistic combinations of the gait parameters and their correlations, but are less successful in reproducing genuine kinetic and kinematics profiles.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Manjila, Sunil, Gagandeep Singh, Ayham M. Alkhachroum y Ciro Ramos-Estebanez. "Understanding Edward Muybridge: historical review of behavioral alterations after a 19th-century head injury and their multifactorial influence on human life and culture". Neurosurgical Focus 39, n.º 1 (julio de 2015): E4. http://dx.doi.org/10.3171/2015.4.focus15121.

Texto completo

Resumen

Edward Muybridge was an Anglo-American photographer, well known for his pioneering contributions in photography and his invention of the “zoopraxiscope,” a forerunner of motion pictures. However, this 19th-century genius, with two original patents in photographic technology, made outstanding contributions in art and neurology alike, the latter being seldom acknowledged. A head injury that he sustained changed his behavior and artistic expression. The shift of his interests from animal motion photography to human locomotion and gait remains a pivotal milestone in our understanding of patterns in biomechanics and clinical neurology, while his own behavioral patterns, owing to an injury to the orbitofrontal cortex, remain a mystery even for cognitive neurologists. The behavioral changes he exhibited and the legal conundrum that followed, including a murder of which he was acquitted, all depict the complexities of his personality and impact of frontal lobe injuries. This article highlights the life journey of Muybridge, drawing parallels with Phineas Gage, whose penetrating head injury has been studied widely. The wide sojourn of Muybridge also illustrates the strong connections that he maintained with Stanford and Pennsylvania universities, which were later considered pinnacles of higher education on the two coasts of the United States.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Kelly, Luke A., Andrew G. Cresswell, Sebastien Racinais, Rodney Whiteley y Glen Lichtwark. "Intrinsic foot muscles have the capacity to control deformation of the longitudinal arch". Journal of The Royal Society Interface 11, n.º 93 (6 de abril de 2014): 20131188. http://dx.doi.org/10.1098/rsif.2013.1188.

Texto completo

Resumen

The human foot is characterized by a pronounced longitudinal arch (LA) that compresses and recoils in response to external load during locomotion, allowing for storage and return of elastic energy within the passive structures of the arch and contributing to metabolic energy savings. Here, we examine the potential for active muscular contribution to the biomechanics of arch deformation and recoil. We test the hypotheses that activation of the three largest plantar intrinsic foot muscles, abductor hallucis, flexor digitorum and quadratus plantae is associated with muscle stretch in response to external load on the foot and that activation of these muscles (via electrical stimulation) will generate sufficient force to counter the deformation of LA caused by the external load. We found that recruitment of the intrinsic foot muscles increased with increasing load, beyond specific load thresholds. Interestingly, LA deformation and muscle stretch plateaued towards the maximum load of 150% body weight, when muscle activity was greatest. Electrical stimulation of the plantar intrinsic muscles countered the deformation that occurred owing to the application of external load by reducing the length and increasing the height of the LA. These findings demonstrate that these muscles have the capacity to control foot posture and LA stiffness and may provide a buttressing effect during foot loading. This active arch stiffening mechanism may have important implications for how forces are transmitted during locomotion and postural activities as well as consequences for metabolic energy saving.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Human locomotion biomechanics and energetics"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros