Estimation of Hip and Ankle Visco-Elastic Parameters During Quiet Standing

2018 ◽  
Author(s):  
Angel Cerda-Lugo ◽  
Alejandro Gonzalez ◽  
Antonio Cardenas ◽  
Davide Piovesan
Keyword(s):  
Postural Stability ◽  
Degrees Of Freedom ◽  
Balance Control ◽  
The Elderly ◽  
The United States ◽  
Second Order ◽  
Quiet Standing ◽  
Control Parameters ◽  
Inverted Pendulum Model ◽  
Modes Of Vibration

Balance control naturally deteriorates with age, so it comes as no surprise that nearly 30% of the elderly population in the United States report stability problems that lead to difficulty performing daily activities or even falling. Postural stability is an integral task to daily living which is reliant upon the control of the ankle and hip. To this end, the estimation of ankle and hip parameters in quiet standing can be a useful tool when analyzing compensatory actions aimed at maintaining postural stability. Using an analytical approach, this work builds upon the results obtained by the authors and expands it to a two degrees of freedom system where the first two modes of vibration of a standing human are considered. The physiological parameters a second-order Kelvin-Voigt model were estimated for the actuation of the ankle and hip. Estimates were obtained during quiet standing when healthy volunteers were subjected to a step-like perturbation. This paper presents the analysis of a second-order nonlinear system of differential equations representing the control of lumped muscle-tendon units at the ankle and hip. This paper utilizes motion capture measurements to obtain the estimates of the control parameters of the system. The dynamic measurements are utilized to construct a simple time-dependent regression that allows calculating the time-varying estimates of the control and body segment parameters with a single perturbation. This work represents a step forward in estimating the control parameters of human quiet standing where, usually, the analysis is either restricted to the first vibrational mode of an inverted pendulum model or the control parameters are assumed to be time-invariant. The proposed method allows for the analysis of hip related movement in the control of stability and highlights the importance of core muscle training.

scholarly journals Postural Stability Evaluation of Patients Undergoing Vestibular Schwannoma Microsurgery Employing the Inertial Measurement Unit

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Patrik Kutilek ◽  
Zdenek Svoboda ◽  
Ondrej Cakrt ◽  
Karel Hana ◽  
Martin Chovanec
Keyword(s):  
Vestibular Schwannoma ◽  
Postural Stability ◽  
Inertial Measurement Unit ◽  
Balance Control ◽  
Body Movement ◽  
Quiet Standing ◽  
Measurement Unit ◽  
Major Drawback ◽  
Inertial Measurement ◽  
Physical Quantities

The article focuses on a noninvasive method and system of quantifying postural stability of patients undergoing vestibular schwannoma microsurgery. Recent alternatives quantifying human postural stability are rather limited. The major drawback is that the posturography system can evaluate only two physical quantities of body movement and can be measured only on a transverse plane. A complex movement pattern can be, however, described more precisely while using three physical quantities of 3-D movement. This is the reason why an inertial measurement unit (Xsens MTx unit), through which we obtained 3-D data (three Euler angles or three orthogonal accelerations), was placed on the patient’s trunk. Having employed this novel method based on the volume of irregular polyhedron of 3-D body movement during quiet standing, it was possible to evaluate postural stability. To identify and evaluate pathological balance control of patients undergoing vestibular schwannoma microsurgery, it was necessary to calculate the volume polyhedron using the 3-D Leibniz method and to plot three variables against each other. For the needs of this study, measurements and statistical analysis were made on nine patients. The results obtained by the inertial measurement unit showed no evidence of improvement in postural stability shortly after surgery (4 days). The results were consistent with the results obtained by the posturography system. The evaluated translation variables (acceleration) and rotary variables (angles) measured by the inertial measurement unit correlate strongly with the results of the posturography system. The proposed method and application of the inertial measurement unit for the purpose of measuring patients with vestibular schwannoma appear to be suitable for medical practice. Moreover, the inertial measurement unit is portable and, when compared to other traditional posturography systems, economically affordable. Inertial measurement units can alternatively be implemented in mobile phones or watches.

Investigating the Nonlinear Dynamics of Human Balance Using Topological Data Analysis

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.

Investigating the Nonlinear Dynamics of Human Balance Using Topological Data Analysis

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.

Effect of Osteopathic Manipulative Treatment Protocol on Balance in the Elderly

2011 ◽  
Author(s):  
Daniel Lopez ◽  
Hollis King ◽  
Janice Knebl ◽  
Victor Kosmopoulos ◽  
DeRaan Collins ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Postural Stability ◽  
Balance Control ◽  
Treatment Protocol ◽  
The Elderly ◽  
Osteopathic Manipulative Treatment ◽  
Control Structures ◽  
Outcome Measurements

The purpose of this study it to understand the effect of Osteopathic Manipulative Treatment (OMT) on vestibular balance control structures. It was hypothesized that following an OMT treatment protocol, elderly patients would show significant improvement in empirical outcome measurements used to quantify postural stability.

Footwear Interventions

2013 ◽  
Vol 103 (6) ◽  
pp. 516-533 ◽  
Author(s):  
Anna L. Hatton ◽  
Keith Rome ◽  
John Dixon ◽  
Denis J. Martin ◽  
Patrick O. McKeon
Keyword(s):  
Older People ◽  
Balance Control ◽  
Dynamic Balance ◽  
The Elderly ◽  
Quiet Standing ◽  
Long Term Effects ◽  
Balance Performance ◽  
Dynamic Movement ◽  
Balance Task ◽  
Older Populations

Footwear interventions, including shoe insoles and foot orthoses, have the capacity to enhance balance control and gait in older people. This review assessed the evidence for the effect of footwear interventions on static and dynamic balance performance and gait in older populations and explored proposed theories for underlying sensorimotor and mechanical mechanisms. We searched the Medline, EMBASE, CINAHL (the Cumulative Index to Nursing and Allied Health Literature), and AMED databases and conducted hand searches. Of 115 relevant articles screened, 14 met the predefined inclusion criteria. Articles were grouped into one of three categories based on balance task (static balance performance during quiet standing, dynamic balance performance during walking, and dynamic balance performance during perturbed standing or functional tasks) and were scored for methodological quality using the Downs and Black Quality Index tool. Footwear interventions seem to alter underlying strategies controlling static and dynamic movement patterns through a combination of sensorimotor and mechanical mechanisms in older people, including those with chronic sensory and musculoskeletal conditions. Evidence shows a consistent trend toward footwear interventions markedly improving lateral stability measures, which are predictors of falls in the elderly. In-depth investigation of neurophysiologic responses to footwear interventions is necessary to help confirm any sensorimotor adaptations. The long-term effects of footwear interventions on balance, gait, and the prevention of falls in older people require further investigation. (J Am Podiatr Med Assoc 103(6): 516–533, 2013)

A Third-Order Model of Hip and Ankle Joints During Balance Recovery: Modeling and Parameter Estimation

2019 ◽  
Vol 14 (10) ◽  
Author(s):  
Alejandro González ◽  
Angel Cerda-Lugo ◽  
Antonio Cardenas ◽  
Mauro Maya ◽  
Davide Piovesan
Keyword(s):  
Postural Stability ◽  
Degrees Of Freedom ◽  
The Elderly ◽  
Skeletal Structure ◽  
Third Order ◽  
Severe Injuries ◽  
Ankle Joints ◽  
Fall Recovery ◽  
Muscle Models ◽  
Balance Mechanism

Abstract Postural stability is important in everyday life as falls can cause severe injuries. Risk of injuries is higher in the elderly whose balance is often impaired. Modeling postural stability and the parameters that govern it is important to understand the balance mechanism and allow for the development of fall prevention strategies. Several mathematical models have been proposed to represent postural stability of bipeds. These models differ on the number of degrees-of-freedom (DOF) of the skeletal structure, force generation function for the muscle models, and capability to change their behavior as a function of the task. This work proposes a nonlinear model that captures fall recovery using a hip–ankle strategy. The muscle actuation is modeled as a third-order Poynting–Thomson's (PT) mechanical system where muscles and tendons are represented as lumped parameters actuating the aforementioned joints. Both a regression technique and a Kalman Filter (KF) are used to estimate the muscle–tendon parameters of the model. With a good model, the direct estimation of these parameters would allow clinicians to improve postural stability in the elderly, monitor the deterioration of the physical condition in individuals affected by neuro-degenerative diseases, and develop rehabilitation appropriate processes.

scholarly journals Can hearing amplification improve presbyvestibulopathy and/or the risk-to-fall ?

2020 ◽  
Author(s):  
Arne Ernst ◽  
Dietmar Basta ◽  
Philipp Mittmann ◽  
Rainer O. Seidl
Keyword(s):  
Cochlear Implants ◽  
Hearing Aids ◽  
Postural Stability ◽  
Standardized Test ◽  
Balance Control ◽  
The Elderly ◽  
Future Research ◽  
Temporal Orientation ◽  
Auditory Information ◽  
Spatio Temporal

Abstract Purpose The decline of sensory systems during aging has been widely investigated and several papers have correlated the visual, hearing and vestibular systems and the consequences of their functional degeneration. Hearing loss and presbyvestibulopathy have been found to be positively correlated as is with the risk-to-fall. Material and methods The present study was therefore designed as systematic review (due to PRISMA criteria) which should correlate hearing amplification by hearing aids and/or cochlear implants with balance outcome. However, the literature review (Cochrane, PubMed) revealed ten paper (prospective, controlled trials and acute trials) with heterogenous patient popiulations and non-uniform outcome measures (i.e., gait analysis, questionnaires, postural stabilometry) so that no quantitative, statistical analysis could be performed. Results The qualitative analysis oft he identified studies showed that hearing amplification in the elderly improves spatio-temporal orientation (particularly with cochlear implants) and that the process of utilizing auditory information for balance control takes some time (i.e., the neuroplasticity-based, learning processes), usually some months in cochlear implantees. Discussion Hearing and balance function degenerate independently from each other and large interindividual differences require a separate neurotological examination of each patient. However, hearing amplification is most helpful to improve postural stability, particularly in the elderly. Future research should focus on controlled, prospective clinical trials where a standardized test battery covering the audiological and neurotological profile of each elderly patient pre/post prescription of hearing aids and/or cochlear implantation should be followed up (for at least 1 year) so that also the balance improvements and the risk-to-fall can be reliably assessed (e.g., by mobile posturography and standardized questionnaires, e.g., the DHI).

The Effect of Unilateral Osteoarthritis of the Hip on Postural Balance Disorders

2016 ◽  
Vol 26 (6) ◽  
pp. 567-572 ◽  
Author(s):  
Aleksandra Truszczyńska ◽  
Zbigniew Trzaskoma ◽  
Jerzy Białecki ◽  
Justyna Drzał-Grabiec ◽  
Emilia Dadura ◽  
...  
Keyword(s):  
Postural Stability ◽  
Balance Control ◽  
Significant Risk ◽  
Quiet Standing ◽  
Study Group ◽  
Ageing Population ◽  
Total Hip ◽  
Eyes Closed ◽  
Lateral Plane ◽  
Risk Factors For Falls

Background Postural stability is of great importance because imbalances and muscle weakness are significant risk factors for falls experienced by the elderly. Hip arthrosis, which causes pain and gait disorders that affect balance control, is common in the ageing population. Aim The aim of this study was to assess postural stability in patients with unilateral hip arthrosis before total hip arthroplasty. Methods The study population consisted of 52 patients with hip arthrosis (study group) and 47 subjects with no history of clinical symptoms of hip pain. The groups did not differ statistically in terms of age and BMI. Static balance was assessed by conducting a quantitative analysis of balance reaction parameters in a quiet standing position with the eyes open and closed. Results Analysis of the collected data revealed numerous statistically significant differences between patients with unilateral hip arthrosis before total hip arthoplasty and the asymptomatic group for parameters tested with eyes closed (p<0.05). We observed higher values of total length of centre of pressure (COP), sway path (SP), length of COP path in the medial-lateral plane (SPML), maximal amplitude between the 2 most distant points in the medial-lateral plane (MaxML), mean COP velocity (MV), and mean COP velocity in medial-lateral (MVML) in the study group.

scholarly journals ASSESSMENT OF POSTURAL INSTABILITY IN PATIENTS WITH A NEUROLOGICAL DISORDER USING A TRI-AXIAL ACCELEROMETER

2015 ◽  
Vol 55 (4) ◽  
pp. 229 ◽  
Author(s):  
Lenka Hanakova ◽  
Vladimir Socha ◽  
Jakub Schlenker ◽  
Ondrej Cakrt ◽  
Patrik Kutilek
Keyword(s):  
Neurological Disorder ◽  
Postural Stability ◽  
Healthy Subjects ◽  
Quantitative Method ◽  
Balance Control ◽  
Three Dimensional ◽  
Quiet Standing ◽  
Progressive Cerebellar Ataxia ◽  
Set Of Points ◽  
Confidence Ellipsoid

<span lang="EN-US">Current techniques for quantifying human postural stability during quiet standing have several limitations. The main problem is that only two movement variables are evaluated, though a better description of complex three-dimensional (3-D) movements can be provided with the use of three variables. A single tri-axial accelerometer placed on the trunk was used to measure 3-D data.<br />We are able to evaluate 3-D movements using a method based on the volume of confidence ellipsoid (VE) of the set of points obtained by plotting three accelerations against each other. Our method was used to identify and evaluate pathological balance control. In this study, measurements were made of patients with progressive cerebellar ataxia, and also control measurements of healthy subjects, and a statistical analysis was performed. The results show that the VEs of the neurological disorder patients are significantly larger than the VEs of the healthy subjects. It can be seen that the quantitative method based on VE is very sensitive for identifying changes in stability, and that it is able to distinguish between neurological disorder patients and healthy subjects.<br /></span>

The Unusual Cruelty of Nursing Homes Behind Bars

2020 ◽  
Vol 32 (5) ◽  
pp. 264-271
Author(s):  
Rachel E. López
Keyword(s):  
Nursing Homes ◽  
Human Dignity ◽  
Prison Population ◽  
Financial Burden ◽  
The Elderly ◽  
The United States ◽  
Term Care ◽  
Trained Staff ◽  
State Prisons ◽  
The Cost

The elderly prison population continues to rise along with higher rates of dementia behind bars. To maintain the detention of this elderly population, federal and state prisons are creating long-term care units, which in turn carry a heavy financial burden. Prisons are thus gearing up to become nursing homes, but without the proper trained staff and adequate financial support. The costs both to taxpayers and to human dignity are only now becoming clear. This article squarely addresses the second dimension of this carceral practice, that is the cost to human dignity. Namely, it sets out why indefinitely incarcerating someone with dementia or other neurocognitive disorders violates the Eighth Amendment of the United States Constitution’s prohibition on cruel and unusual punishment. This conclusion derives from the confluence of two lines of U.S. Supreme Court precedent. First, in Madison v. Alabama, the Court recently held that executing someone (in Madison’s case someone with dementia) who cannot rationally understand their sentence amounts to cruel and unusual punishment. Second, in line with Miller v. Alabama, which puts life without parole (LWOP) sentences in the same class as death sentences due to their irrevocability, this holding should be extended to LWOP sentences. Put another way, this article explains why being condemned to life is equivalent to death for someone whose neurodegenerative disease is so severe that they cannot rationally understand their punishment.

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