Foot Force Control During Walking Tasks in Humans

Foot Force Control During Walking Tasks in Humans PDF Author: Nathanael J. Oats
Publisher:
ISBN:
Category :
Languages : en
Pages : 144

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Foot Force Control During Walking Tasks in Humans

Foot Force Control During Walking Tasks in Humans PDF Author: Nathanael J. Oats
Publisher:
ISBN:
Category :
Languages : en
Pages : 144

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Self-presentation

Self-presentation PDF Author: Mark R Leary
Publisher: Routledge
ISBN: 0429977018
Category : Social Science
Languages : en
Pages : 438

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Book Description
This book is about the ways which human behavior is affected concerns with people may be doing, their public impressions they typically prefer that No matter what else other people perceive them in certain desired ways and not perceive them in other, undesired ways. Put simply, human beings have a pervasive and ongoing concern with their self-presentations. Sometimes they act in ceflain ways just to make a particular impression on someone else mras when a job applicant responds inthat will satisfactorily impress the interviewer. But more often, people 5 concerns with others’ impressions simply constrain their behavioural options. Most of the time inclined to do things that will lead others to see us as incompetent, inwnoral, maladjusted, or otherwise socially undesirable. As a result, our concerns with others’ impressions limit what we are willing to do.Self-presentation almotives underlie and pervade near corner of interpersonal life.

Clinical Gait Analysis

Clinical Gait Analysis PDF Author: Christopher Kirtley
Publisher: Elsevier Health Sciences
ISBN: 0443100098
Category : Medical
Languages : en
Pages : 328

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Book Description
Provides a detailed clinical introduction to the application of biomechanics to the understanding and treatment of walking disorders. Practical issues in the performance of a three-dimensional clinical gait analysis are covered, together with several clinical cases illustrating the interpretation of findings. These cases also demonstrate the use of a variety of treatment methodologies, including physical therapy, walking aids, prosthetics and orthotics, botulinum toxin and surgery.

Modeling, Simulation and Optimization of Bipedal Walking

Modeling, Simulation and Optimization of Bipedal Walking PDF Author: Katja Mombaur
Publisher: Springer Science & Business Media
ISBN: 3642363687
Category : Technology & Engineering
Languages : en
Pages : 289

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Book Description
The model-based investigation of motions of anthropomorphic systems is an important interdisciplinary research topic involving specialists from many fields such as Robotics, Biomechanics, Physiology, Orthopedics, Psychology, Neurosciences, Sports, Computer Graphics and Applied Mathematics. This book presents a study of basic locomotion forms such as walking and running is of particular interest due to the high demand on dynamic coordination, actuator efficiency and balance control. Mathematical models and numerical simulation and optimization techniques are explained, in combination with experimental data, which can help to better understand the basic underlying mechanisms of these motions and to improve them. Example topics treated in this book are Modeling techniques for anthropomorphic bipedal walking systems Optimized walking motions for different objective functions Identification of objective functions from measurements Simulation and optimization approaches for humanoid robots Biologically inspired control algorithms for bipedal walking Generation and deformation of natural walking in computer graphics Imitation of human motions on humanoids Emotional body language during walking Simulation of biologically inspired actuators for bipedal walking machines Modeling and simulation techniques for the development of prostheses Functional electrical stimulation of walking.

Mechanics and Control of Human Balance

Mechanics and Control of Human Balance PDF Author: Matthew Millard
Publisher:
ISBN:
Category :
Languages : en
Pages : 145

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Book Description
A predictive, forward-dynamic model and computer simulation of human gait has important medical and research applications. Most human simulation work has focused on inverse dynamics studies to quantify bone on bone forces and muscle loads. Inverse dynamics is not predictive - it works backwards from experimentally measured motions in an effort to find the forces that caused the motion. In contrast, forward dynamics determines how a mechanism will move without the need for experimentation. Most of the forward dynamic gait simulations reported consider only one step, foot contact is not modeled, and balance controllers are not used. This thesis addresses a few of the shortcomings of current human gait simulations by contributing an experimentally validated foot contact model, a model-based stance controller, and an experimentally validated model of the relationship between foot placement location and balance. The goal of a predictive human gait simulation is to determine how a human would walk under a condition of interest, such as walking across a slippery floor, using a new lower limb prosthesis, or with reduced leg strength. To achieve this goal, often many different gaits are simulated and the one that is the most human-like is chosen as the prediction for how a person would move. Thus it is necessary to quantify how `human-like' a candidate gait is. Human walking is very efficient, and so, the metabolic efficiency of the candidate gait is most often used to measure the performance of a candidate gait. Muscles consume metabolic energy as a function of the tension they develop and the rate at which they are contracting. Muscle tension is developed, and contractions are made in an effort generate torques about joints in order to make them move. To predict human gait, it is necessary for the simulation to be able to walk in such a way that the simulated leg joints use similar joint torques and kinematics as a human leg does, all while balancing the body. The joint torques that the legs must develop to propel the body forward, and balance it, are heavily influenced by the ground reaction forces developed between the simulated foot and the ground. A predictive gait simulation must be able to control the model so that it can walk, and remain balanced while generating ground reaction force profiles that are similar to experimentally observed human ground reaction force profiles. Ground reaction forces are shaped by the way the foot interacts with the ground, making it very important to model the human foot accurately. Most continuous foot contact models present in the literature have been experimentally validated using pendulum impact methods that have since been shown to produce inaccurate results. The planar foot contact model developed as part of this research was validated in-vivo using conventional force plates and optical tracking markers. The experimental data was also highly useful for developing a computationally efficient foot model by identifying the dominant contact properties of a real foot (during walking), without the complexity of modelling the 26 bones, 33 joints, over 90 ligaments, and the network of muscles that are in a real foot. Both ground reaction forces and the balance of the model are heavily influenced by the way the stance limb is controlled. Anthropomorphic multibody models typically have a fragile sense of balance, and ground reaction force profiles that do not look similar to experimentally measured human ground reaction force profiles. In contrast, the simple point-mass spring-loaded-inverted-pendulum (SLIP) can be made to walk or run in a balanced manner with center-of-mass (COM) kinematics and ground reaction force profiles that could be mistaken for the equivalent human data. A stance limb controller is proposed that uses a planar SLIP to compute a reference trajectory for a planar anthropomorphic multibody gait model. The torso of the anthropomorphic model is made to track the computed trajectory of the SLIP using a control system. The aim of this partitioned approach to gait simulation is to endow the anthropomorphic model with the human-like gait of the simpler SLIP model.

Neuro-motor control and feed-forward models of locomotion in humans

Neuro-motor control and feed-forward models of locomotion in humans PDF Author: Marco Iosa
Publisher: Frontiers Media SA
ISBN: 2889196143
Category : Human locomotion
Languages : en
Pages : 192

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Book Description
Locomotion involves many different muscles and the need of controlling several degrees of freedom. Despite the Central Nervous System can finely control the contraction of individual muscles, emerging evidences indicate that strategies for the reduction of the complexity of movement and for compensating the sensorimotor delays may be adopted. Experimental evidences in animal and lately human model led to the concept of a central pattern generator (CPG) which suggests that circuitry within the distal part of CNS, i.e. spinal cord, can generate the basic locomotor patterns, even in the absence of sensory information. Different studies pointed out the role of CPG in the control of locomotion as well as others investigated the neuroplasticity of CPG allowing for gait recovery after spinal cord lesion. Literature was also focused on muscle synergies, i.e. the combination of (locomotor) functional modules, implemented in neuronal networks of the spinal cord, generating specific motor output by imposing a specific timing structure and appropriate weightings to muscle activations. Despite the great interest that this approach generated in the last years in the Scientific Community, large areas of investigations remain available for further improvement (e.g. the influence of afferent feedback and environmental constrains) for both experimental and simulated models. However, also supraspinal structures are involved during locomotion, and it has been shown that they are responsible for initiating and modifying the features of this basic rhythm, for stabilising the upright walking, and for coordinating movements in a dynamic changing environment. Furthermore, specific damages into spinal and supraspinal structures result in specific alterations of human locomotion, as evident in subjects with brain injuries such as stroke, brain trauma, or people with cerebral palsy, in people with death of dopaminergic neurons in the substantia nigra due to Parkinson’s disease, or in subjects with cerebellar dysfunctions, such as patients with ataxia. The role of cerebellum during locomotion has been shown to be related to coordination and adaptation of movements. Cerebellum is the structure of CNS where are conceivably located the internal models, that are neural representations miming meaningful aspects of our body, such as input/output characteristics of sensorimotor system. Internal model control has been shown to be at the basis of motor strategies for compensating delays or lacks in sensorimotor feedbacks, and some aspects of locomotion need predictive internal control, especially for improving gait dynamic stability, for avoiding obstacles or when sensory feedback is altered or lacking. Furthermore, despite internal model concepts are widespread in neuroscience and neurocognitive science, neurorehabilitation paid far too little attention to the potential role of internal model control on gait recovery. Many important scientists have contributed to this Research Topic with original studies, computational studies, and review articles focused on neural circuits and internal models involved in the control of human locomotion, aiming at understanding the role played in control of locomotion of different neural circuits located at brain, cerebellum, and spinal cord levels.

The Biomechanics and Motor Control of Human Gait

The Biomechanics and Motor Control of Human Gait PDF Author: David A. Winter
Publisher:
ISBN:
Category : Biomechanics
Languages : en
Pages : 160

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Understanding the Human Foot

Understanding the Human Foot PDF Author: James Earls
Publisher: North Atlantic Books
ISBN: 1623176581
Category : Medical
Languages : en
Pages : 250

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Book Description
An essential resource for bodyworkers, physical therapists, and sports medicine practitioners--a vital guide to understanding the anatomy, form, and mechanics of the human foot. Understanding the Human Foot is a full-color, up-to-date overview of the structure and function of the foot, written for physical therapists and movement practitioners looking to deepen their understanding of holistic anatomy. Readers will gain perspective on the impacts of foot shape; the interdependence of form and function; and the cellular processes that determine how our tissue is designed. Most importantly, author James Earls demonstrates how the foot relates to and interacts with the rest of the body during movement, laying the groundwork for a comprehensive holistic approach to assessing, troubleshooting, and addressing functional and structural foot issues. Starting with big-picture questions--what is a foot, and what is it used for? How does it work, both on its own and as part of a whole?--before zeroing in on the 26 bones, 33 joints, and many muscles that make up the foot, Earls teaches anatomy the way he wishes he'd been taught 30 years ago: with a holistic emphasis on interrelated systems, real-life applications, and approachable, easy-to-understand language. He shares: Full-color illustrations for easy reference and comprehensive understanding An overview of the bones, ligaments, and extrinsic and intrinsic muscles of the foot How your gait impacts the rest of the body--and can cause problems as high up as the neck and shoulders How to assess structural problems of the foot Corrective exercises A footwear guide to choosing the best shoe for your foot type

Foot Force Direction Control During Leg Pushes Against Fixed and Moving Pedals in Persons Post-stroke

Foot Force Direction Control During Leg Pushes Against Fixed and Moving Pedals in Persons Post-stroke PDF Author: Lynn M. Rogers
Publisher:
ISBN:
Category :
Languages : en
Pages : 202

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Initiation and Control of Gait from First Principles: A Mathematically Animated Model of the Foot

Initiation and Control of Gait from First Principles: A Mathematically Animated Model of the Foot PDF Author: Craig Nevin
Publisher: Universal-Publishers
ISBN: 1599423294
Category :
Languages : en
Pages :

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Book Description
This thesis examines the anatomical locations of the dynamic pressures that create the first five footprints when a standing person starts to walk. It is hypothesized that the primary activity starts with the dorsiflexion or lifting of the great toe. Consequently, the metatarsophalangeal region of the forefoot was studied from three directions. Viewed side-on, the great toe free-body is found from a detailed post hoc analysis of previous kinematic data obtained from cadavers to operate as a cam. The cam model also follows closely from Aristotle's ancient description of the hinged instrument of animate motion. Viewed in coronal cross-section, the first metatarsal torsion strength was estimated in 13 humans, 1 gorilla, 3 chimpanzees, 1 orangutan and 1 baboon set of dry-bone specimens of the hands and feet. The first metatarsal bone alone contributes 43% of the total strength of all the metatarsal bones. A result unique amongst the hominids and apes studied. Viewed in horizontal plan, the dynamic components and principle axes of the footprints of 54 barefoot humans (32 male, 22 female, age 32 +-11 years) were studied whilst standing on a 0.5m pressure plate, and then immediately when walking over a 2m plate (4 sensors per cm2 sampled at 100hz). Two footprints were obtained during the initial stance posture, and the first three footprints of the initial walk. Three new principles of animate motion were deduced from the divergent results obtained from complete and dissected cadavers: The metatarsal cam (from the sagittal side view) the ground reaction torque (from the frontal coronal view) and the amputation artifact. The philosophy of experimenting on inanimate cadavers rather than living subjects was intensively researched. Instead of assuming that gait is a uniform or regular motion as is usual, the foot was analyzed rather as if it was a beam attached to the ground. Engineering equations were used to determine the flexural properties of the foot every 0.01 seconds, including the principle axes, radius of gyration and the local shear stresses on the sensors spaced 5-7mm apart. A sequence of these impressions creates a mathematically animated model of the footprint. The local force under the foot was normalized against both the total force and contact duration. The forces under the foot were each divided between 10 anatomical regions using individual masks for each foot strike. Producing a 54-subject database from which the normal behavior of the foot could be quantified. The group showed a surprisingly low right foot step-off dominance of only 54%. The combination of the radius of gyration and impulse in particular produces a succinct but powerful summary of the footprint during dynamic activity. The initial angle and magnitudes of the loads that are applied and removed demonstrates that the body first rocks onto the heels after the instruction to walk is given. The feet simultaneously invert and their arches rise off the ground as anticipated. The principle axes were then animated in a mathematical four-dimensional model. The horizontal radius of gyration is on average 5 cm during heel strike, but increases to 20 cm as the forefoot comes into contact with the ground, finally rising to 25 cm at toe-off. Significantly the applied load during the fore-foot loading phase is more widely distributed than the load being removed. A new and unanticipated result that is believed to be a special characteristic of the animate foot. The standard deviation of the force under the great toe is the first mechanical parameter to converge in the 54 subjects, conclusively verifying the hypothesis that the great toe both initiates and controls gait.