Balance Control for an Active Leg Exoskeleton Based on Human Balance Strategies

Destabilization of human balance control by static and dynamic head tilts

Gait & Posture ◽

10.1016/j.gaitpost.2005.04.009 ◽

2006 ◽

Vol 23 (3) ◽

pp. 315-323 ◽

Cited By ~ 59

Author(s):

William H. Paloski ◽

Scott J. Wood ◽

Alan H. Feiveson ◽

F. Owen Black ◽

Emma Y. Hwang ◽

...

Keyword(s):

Balance Control ◽

Dynamic Head ◽

Human Balance ◽

Human Balance Control

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Probing the human vestibular system with galvanic stimulation

Journal of Applied Physiology ◽

10.1152/japplphysiol.00008.2004 ◽

2004 ◽

Vol 96 (6) ◽

pp. 2301-2316 ◽

Cited By ~ 357

Author(s):

Richard C. Fitzpatrick ◽

Brian L. Day

Keyword(s):

Balance Control ◽

Semicircular Canals ◽

Vestibular Nuclei ◽

Vestibular Stimulation ◽

Otolith Organs ◽

Sources Of Information ◽

Electrophysiological Studies ◽

Human Balance ◽

Cortical Inputs ◽

Vestibular Organs

Galvanic vestibular stimulation (GVS) is a simple, safe, and specific way to elicit vestibular reflexes. Yet, despite a long history, it has only recently found popularity as a research tool and is rarely used clinically. The obstacle to advancing and exploiting GVS is that we cannot interpret the evoked responses with certainty because we do not understand how the stimulus acts as an input to the system. This paper examines the electrophysiology and anatomy of the vestibular organs and the effects of GVS on human balance control and develops a model that explains the observed balance responses. These responses are large and highly organized over all body segments and adapt to postural and balance requirements. To achieve this, neurons in the vestibular nuclei receive convergent signals from all vestibular receptors and somatosensory and cortical inputs. GVS sway responses are affected by other sources of information about balance but can appear as the sum of otolithic and semicircular canal responses. Electrophysiological studies showing similar activation of primary afferents from the otolith organs and canals and their convergence in the vestibular nuclei support this. On the basis of the morphology of the cristae and the alignment of the semicircular canals in the skull, rotational vectors calculated for every mode of GVS agree with the observed sway. However, vector summation of signals from all utricular afferents does not explain the observed sway. Thus we propose the hypothesis that the otolithic component of the balance response originates from only the pars medialis of the utricular macula.

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Incorporating Voluntary Knee Flexion Into Nonanticipatory Balance Corrections

Journal of Neurophysiology ◽

10.1152/jn.01303.2006 ◽

2007 ◽

Vol 98 (5) ◽

pp. 3047-3059 ◽

Cited By ~ 12

Author(s):

Lars B. Oude Nijhuis ◽

Bastiaan R. Bloem ◽

Mark G. Carpenter ◽

John H. J. Allum

Keyword(s):

Knee Flexion ◽

Balance Control ◽

Critical Role ◽

Support Surface ◽

Trunk Flexion ◽

Postural Perturbation ◽

Automatic Balance ◽

Human Balance ◽

Balance Deficits ◽

Balance Corrections

Knee movements play a critical role in most balance corrections. Loss of knee flexibility may cause postural instability. Conversely, trained voluntary knee flexions executed during balance corrections might help to overcome balance deficits. We examined whether bilateral knee flexion could be added to automatic balance corrections generated by sudden balance perturbations. We investigated how this could be achieved and whether it improved or worsened balance control. Twenty-four healthy subjects participated in three different test conditions, in which they had to flex their knees following an auditory cue (VOLUNTARY condition), had to restore their balance in response to multidirectional rotations of a support surface (REACTIVE condition), or the combination of these two (COMBINED condition). A new variable set (PREDICTED), calculated as the mathematical sum of VOLUNTARY and REACTIVE, was compared with the COMBINED variable set. COMBINED responses following forward rotations were close to PREDICTED, or greater, suggesting adequate integration of knee flexion into the automatic balance reactions. For backward rotations, the COMBINED condition resulted in several near-falls, and this was generally associated with smaller knee flexion and smaller EMG responses. Subjects compensated by using greater trunk flexion and arm movements. Activity in several muscles displayed earlier onsets for the COMBINED condition following backward rotations. We conclude that healthy adults can incorporate voluntary knee flexion into their automatic balance corrections and that this depends on the direction of the postural perturbation. These findings highlight the flexibility of the human balance repertoire and underscore both the advantages and limitations of using trained voluntary movements to aid balance corrections in man.

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Toward Stochastic Explanation of Neutrally Stable Delayed Feedback Model of Human Balance Control

Proceedings of the ISCIE International Symposium on Stochastic Systems Theory and its Applications ◽

10.5687/sss.2011.244 ◽

2011 ◽

Vol 2011 (0) ◽

pp. 244-249 ◽

Cited By ~ 1

Author(s):

Katsutoshi Yoshida

Keyword(s):

Balance Control ◽

Delayed Feedback ◽

Feedback Model ◽

Human Balance ◽

Human Balance Control

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Hardware-In-the-Loop Equipment for the Development of an Automatic Perturbator for Clinical Evaluation of Human Balance Control

Applied Sciences ◽

10.3390/app10248886 ◽

2020 ◽

Vol 10 (24) ◽

pp. 8886

Author(s):

Carlo Ferraresi ◽

Daniela Maffiodo ◽

Walter Franco ◽

Giovanni Gerardo Muscolo ◽

Carlo De Benedictis ◽

...

Keyword(s):

Balance Control ◽

The Body ◽

Clinical Settings ◽

Control Analysis ◽

Hardware In The Loop ◽

Control Laws ◽

Component Selection ◽

Risk Of Falls ◽

Human Balance ◽

Human Balance Control

Nowadays, increasing attention is being paid to techniques aimed at assessing a subject’s ability to maintain or regain control of balance, thus reducing the risk of falls. To this end, posturographic analyses are performed in different clinical settings, both in unperturbed and perturbed conditions. This article presents a new Hardware-In-the-Loop (HIL) equipment designed for the development of an automatic perturbator for postural control analysis, capable of providing controlled mechanical stimulation by means of an impulsive force exerted on a given point of the body. The experimental equipment presented here includes the perturbator and emulates its interaction with both the subject’s body and the operator performing the test. The development of the perturbator and of the entire HIL equipment is described, including component selection, modeling of the entire system, and experimentally verified simulations used to study and define the most appropriate control laws.

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Investigating the Nonlinear Dynamics of Human Balance Using Topological Data Analysis

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4047937 ◽

2020 ◽

Vol 15 (9) ◽

Author(s):

Kyle W. Siegrist ◽

Ryan M. Kramer ◽

James R. Chagdes

Keyword(s):

Time Series ◽

Postural Stability ◽

Inverted Pendulum ◽

Balance Control ◽

Neuromuscular Diseases ◽

Neuromuscular Control ◽

Topological Data Analysis ◽

Control Parameters ◽

Human Balance ◽

Neuromuscular Impairment

Abstract Understanding the mechanisms behind human balance has been a subject of interest as various postural instabilities have been linked to neuromuscular diseases (e.g., Parkinson's, multiple sclerosis, and concussion). This paper presents a method to characterize an individual's postural stability and estimate of their neuromuscular feedback control parameters. The method uses a generated topological mapping between a subject's experimental data and a dataset consisting of time-series realizations generated using an inverted pendulum mathematical model of upright balance. The performance of the method is quantified using a set of validation time-series realizations with known stability and neuromuscular control parameters. The method was found to have an overall sensitivity of 85.1% and a specificity of 91.9%. Furthermore, the method was most accurate when identifying limit cycle oscillations (LCOs) with a sensitivity of 91.1% and a specificity of 97.6%. Such a method has the capability of classifying an individual's stability and revealing possible neuromuscular impairment related to balance control, ultimately providing useful information to clinicians for diagnostic and rehabilitation purposes.

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Investigating the Nonlinear Dynamics of Human Balance Using Topological Data Analysis

Volume 6: 15th International Conference on Multibody Systems, Nonlinear Dynamics, and Control ◽

10.1115/detc2019-98014 ◽

2019 ◽

Author(s):

Kyle W. Siegrist ◽

James R. Chagdes ◽

Ryan M. Kramer

Keyword(s):

Time Series ◽

Postural Stability ◽

Balance Control ◽

Neuromuscular Diseases ◽

Neuromuscular Control ◽

Topological Data Analysis ◽

Control Parameters ◽

Data Set ◽

Human Balance ◽

Neuromuscular Impairment

Abstract Understanding the mechanisms behind human balance has been a subject of interest as various postural instabilities have been linked to neuromuscular diseases (Parkinson’s, multiple sclerosis, and concussion). This paper presents a classification method for an individual’s postural stability and estimation of their neuromuscular feedback control parameters. The method uses a generated topological mapping between a subjects experimental data and a data set consisting of time series realizations generated using an inverted pendulum mathematical model of upright balance. The performance of the method is quantified using a time series realizations with known stability and neuromuscular control parameters. The method was found to have an overall sensitivity of 85.1% and a specificity of 91.9%. Furthermore, the method was most accurate when identifying limit cycle oscillations with a sensitivity of 91.1% and a specificity of 97.6%. Such a method has the capability of classifying an individual’s stability and revealing possible neuromuscular impairment related to balance control, ultimately providing useful information to clinicians for diagnostic and rehabilitation purposes.

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