The Role of Ankle Plantarflexors in Maintaining Dynamic Balance During Human Walking

2012 ◽  
Author(s):  
Richard R. Neptune ◽  
Craig P. McGowan ◽  
Allison L. Hall
Keyword(s):  
Angular Momentum ◽  
Dynamic Balance ◽  
Center Of Mass ◽  
The Body ◽  
Whole Body ◽  
Human Walking ◽  
Ground Reaction Forces ◽  
Reaction Forces ◽  
Anterior Posterior

The regulation of whole-body angular momentum is essential for maintaining dynamic balance during human walking and appears to be tightly controlled during normal and pathological movement (e.g., [1, 2]). The primary mechanism to regulate angular momentum is muscle force generation, which accelerates the body segments and generates ground reaction forces that alter angular momentum about the body’s center-of-mass to restore and maintain dynamic balance. Previous modeling studies have shown the ankle plantarflexors are important contributors to the anterior/posterior, vertical and medial/lateral ground reaction forces during human walking [3, 4], and therefore appear critical to regulating angular momentum and maintaining dynamic balance during walking.

Research on Pre-Slip Gait Mechanical Contributions and Gait Self-Balancing Mechanics during Walking

2012 ◽  
Vol 164 ◽  
pp. 383-386
Author(s):  
Hai Long Su ◽  
Da Wei Zhang
Keyword(s):  
Angular Momentum ◽  
Human Body ◽  
Dynamic Balance ◽  
Human Movement ◽  
The Body ◽  
Whole Body ◽  
Complex Dynamic ◽  
Dynamic Task

Walking is a complex dynamic task that requires the regulation of the whole-body angular momentum to maintain dynamic balance while performing walking subtasks such as propelling the body forward and accelerating the leg into swing. To investigate the characteristic of slips and falls during gait self-balancing, a method was proposed that could better understand the effects of pre-slip gait response biomechanics on the risk for falls. A new segmental model of the human body was developed and this model would be used continuously measured locations from nearly 85 points on the body to produce a dynamic postural record of human movement. The muscles surrounding the hip were found to be most important in maintaining control of the trunk and preventing collapse in response to the forward perturbations (FP).

Rate of Angular Momentum in ZMP Using Efficient DH-Based Recursive Lagrangian

2018 ◽  
Vol 15 (06) ◽  
pp. 1850028
Author(s):  
Hyun-Joon Chung ◽  
Joo H. Kim ◽  
Yujiang Xiang
Keyword(s):  
Angular Momentum ◽  
High Speed ◽  
Direct Method ◽  
Dynamic Balance ◽  
Necessary Condition ◽  
Ground Reaction Forces ◽  
Motion Trajectories ◽  
Global Force ◽  
Reaction Forces ◽  
Zero Moment

Dynamic balance has to be maintained during motions of biped systems when their feet are in contact with the ground. As a necessary condition, this indicates that the calculated zero moment point (ZMP) position should be within the specified foot support region throughout the entire motion. A critical term in the ZMP formulation is the rate of angular momentum (RAM) for each link, which should be evaluated accurately and efficiently in motion planning and simulations. In this study, we propose a recursive Lagrangian method based on Denavit–Hartenberg convention to calculate the RAM for each link and the corresponding sensitivity. This method allows the evaluation of each link’s dynamic contribution to the ZMP position. The effectiveness of the proposed approach is demonstrated by simulating bipedal motions of walking and running along with their comparison against existing approaches (direct method and global force method). The accurate RAM calculation in ZMP based on the proposed approach resulted in the improved motion trajectories and reliable ground reaction forces for high-speed bipedal motion predictions.

Leg design in hexapedal runners

1991 ◽  
Vol 158 (1) ◽  
pp. 369-390 ◽  
Author(s):  
R. J. Full ◽  
R. Blickhan ◽  
L. H. Ting
Keyword(s):  
Ground Reaction Force ◽  
Mechanical Energy ◽  
Reaction Force ◽  
The Body ◽  
Whole Body ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Muscle Forces ◽  
Body Dynamics ◽  
Reaction Forces

Many-legged animals, such as crabs and cockroaches, utilize whole-body mechanics similar to that observed for running bipeds and trotting quadrupedal mammals. Despite the diversity in morphology, two legs in a quadrupedal mammal, three legs in an insect and four legs in a crab can function in the same way as one leg of a biped during ground contact. To explain how diverse leg designs can result in common whole-body dynamics, we used a miniature force platform to measure the ground reaction forces produced by individual legs of the cockroach Blaberus discoidalis. Hexapedal runners were not like quadrupeds with an additional set of legs. In trotting quadrupedal mammals each leg develops a similar ground reaction force pattern that sums to produce the whole-body pattern. At a constant average velocity, each leg pair of the cockroach was characterized by a unique ground reaction force pattern. The first leg decelerated the center of mass in the horizontal direction, whereas the third leg was used to accelerate the body. The second leg did both, much like legs in bipedal runners and quadrupedal trotters. Vertical force peaks for each leg were equal in magnitude. In general, peak ground reaction force vectors minimized joint moments and muscle forces by being oriented towards the coxal joints, which articulate with the body. Locomotion with a sprawled posture does not necessarily result in large moments around joints. Calculations on B. discoidalis showed that deviations from the minimum moments may be explained by considering the minimization of the summed muscle forces in more than one leg. Production of horizontal forces that account for most of the mechanical energy generated during locomotion can actually reduce total muscle force by directing the ground reaction forces through the leg joints. Whole-body dynamics common to two-, four-, six- and eight-legged runners is produced in six-legged runners by three pairs of legs that differ in orientation with respect to the body, generate unique ground reaction force patterns, but combine to function in the same way as one leg of a biped.

Ground reaction forces intersect above the center of mass in single support, but not in double support of human walking

2021 ◽  
Vol 120 ◽  
pp. 110387
Author(s):  
Johanna Vielemeyer ◽  
Roy Müller ◽  
Nora-Sophie Staufenberg ◽  
Daniel Renjewski ◽  
Rainer Abel
Keyword(s):  
Center Of Mass ◽  
Human Walking ◽  
Ground Reaction Forces ◽  
Double Support ◽  
Reaction Forces

scholarly journals Using Biofeedback to Reduce Step Length Asymmetry Impairs Dynamic Balance in People Poststroke

2021 ◽  
pp. 154596832110193
Author(s):  
Sungwoo Park ◽  
Chang Liu ◽  
Natalia Sánchez ◽  
Julie K. Tilson ◽  
Sara J. Mulroy ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Sagittal Plane ◽  
Dynamic Balance ◽  
Objective Measure ◽  
Frontal Plane ◽  
Step Length ◽  
Berg Balance Scale ◽  
Whole Body ◽  
Functional Gait ◽  
Full Body

Background People poststroke often walk with a spatiotemporally asymmetric gait, due in part to sensorimotor impairments in the paretic lower extremity. Although reducing asymmetry is a common objective of rehabilitation, the effects of improving symmetry on balance are yet to be determined. Objective We established the concurrent validity of whole-body angular momentum as a measure of balance, and we determined if reducing step length asymmetry would improve balance by decreasing whole-body angular momentum. Methods We performed clinical balance assessments and measured whole-body angular momentum during walking using a full-body marker set in a sample of 36 people with chronic stroke. We then used a biofeedback-based approach to modify step length asymmetry in a subset of 15 of these individuals who had marked asymmetry and we measured the resulting changes in whole-body angular momentum. Results When participants walked without biofeedback, whole-body angular momentum in the sagittal and frontal plane was negatively correlated with scores on the Berg Balance Scale and Functional Gait Assessment supporting the validity of whole-body angular momentum as an objective measure of dynamic balance. We also observed that when participants walked more symmetrically, their whole-body angular momentum in the sagittal plane increased rather than decreased. Conclusions Voluntary reductions of step length asymmetry in people poststroke resulted in reduced measures of dynamic balance. This is consistent with the idea that after stroke, individuals might have an implicit preference not to deviate from their natural asymmetry while walking because it could compromise their balance. Clinical Trials Number: NCT03916562.

Anterior-posterior ground reaction forces across a range of running speeds in unilateral transfemoral amputees

2020 ◽  
pp. 1-12
Author(s):  
Hiroyuki Sakata ◽  
Satoru Hashizume ◽  
Ryo Amma ◽  
Genki Hisano ◽  
Hiroto Murata ◽  
...  
Keyword(s):  
Ground Reaction Forces ◽  
Reaction Forces ◽  
Transfemoral Amputees ◽  
Anterior Posterior

scholarly journals Can Muscle Stiffness Alone Stabilize Upright Standing?

1999 ◽  
Vol 82 (3) ◽  
pp. 1622-1626 ◽  
Author(s):  
Pietro G. Morasso ◽  
Marco Schieppati
Keyword(s):  
Center Of Pressure ◽  
Center Of Mass ◽  
Muscle Stiffness ◽  
The Body ◽  
Ankle Muscles ◽  
Upright Standing ◽  
Stiffness Control ◽  
Control Patterns ◽  
Physiological Values

A stiffness control model for the stabilization of sway has been proposed recently. This paper discusses two inadequacies of the model: modeling and empiric consistency. First, we show that the in-phase relation between the trajectories of the center of pressure and the center of mass is determined by physics, not by control patterns. Second, we show that physiological values of stiffness of the ankle muscles are insufficient to stabilize the body “inverted pendulum.” The evidence of active mechanisms of sway stabilization is reviewed, pointing out the potentially crucial role of foot skin and muscle receptors.

scholarly journals Collagen drinks for functional nutrition

2018 ◽  
Vol 80 (3) ◽  
pp. 97-103
Author(s):  
L. V. Antipova ◽  
S. A. Storublevtsev ◽  
A. A. Getmanova
Keyword(s):  
Connective Tissue ◽  
Main Part ◽  
Jerusalem Artichoke ◽  
The Body ◽  
Whole Body ◽  
Energy Functions ◽  
Preventive Actions ◽  
Prevention And Treatment ◽  
Experimental Laboratory

In the process of life of the body continuously consumed nutrients that perform plastic and energy functions. The source of nutrients is a variety of foods, consisting of a complex of proteins, fats and carbohydrates, which in the process of digestion are converted into digestible substances. Collagen is the basis of connective tissue and binds the cells in the tissues, creates the frame of the whole body. The gastrointestinal tract, as a system of organs, is no exception and is designed process and extract nutrients from food. Most organs consist of connective tissue, accounting for 60–90% of their mass, which confirms its importance and the role of collagen in this regard can not be estimated. Collagen functions in the body are diverse, one of the main - part in digestion, the violation of which is the cause of diseases such as gastritis and ulcers. For the prevention and treatment of such diseases are very useful liquid collagen-containing food in the form of functional drinks. Developed and obtained in the experimental laboratory a variety of drinks on a collagen basis, with the use of additional broth with sea buckthorn pulp, tincture of dried chicory root powder and broth with the flesh of Jerusalem artichoke. An invaluable contribution to the therapeutic and preventive actions of all these components is proved not only scientifically, but also time-tested.

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