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.

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 Effects of Balance Shoes on Balance and Postural Stability in the Elderly: A Crossover, Controlled, Randomized Single-Blind Study

Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 179
Author(s):  
Nicolas Amiez ◽  
Carole Cometti ◽  
Éric Mouillon ◽  
Marie José Teisseire ◽  
Pascal Chenut ◽  
...  
Keyword(s):  
Elderly People ◽  
Postural Stability ◽  
The Elderly ◽  
Risk Of Falling ◽  
Limits Of Stability ◽  
Healthy Elderly ◽  
Falling Risk ◽  
Familiarization Period ◽  
Healthy Elderly People ◽  
Single Blind

The risk of falling increases with age. Individuals wearing unadapted shoes present an aggravating risk factor. The objective of this study was to determine the effectiveness of specifically designed balance shoes on balance and postural stability in healthy elderly people compared to that of their usual shoes. In total, 21 healthy individuals aged 65–84 years (76.0 ± 8.0 years) performed balance tests (bipedal with open or closed eyes, unipedal with open eyes, limits of stability, and step cadence) while wearing their (i) personal shoes or (ii) balance shoes (Axis Comfort Development©). Three test sessions were conducted with personal and balance shoes. The first served as the baseline, and the other two were performed after a familiarization period of several days with the personal or balance shoes. The perception of balance shoe efficiency was documented using a questionnaire. The balance shoes significantly improved bipedal balance with closed eyes. Moreover, the familiarization period significantly improved unipedal balance with open eyes. Most subjects felt safer and stabler using balance shoes. The investigated specifically designed balance shoes were effective in elderly individuals in improving postural balance compared to personal shoes. The balance shoes could, therefore, reduce the falling risk in healthy elderly people.

TSDT theory for free vibration of functionally graded plates with various material properties

2021 ◽  
Vol 8 (4) ◽  
pp. 691-704
Author(s):  
M. Janane Allah ◽  
◽  
Y. Belaasilia ◽  
A. Timesli ◽  
A. El Haouzi ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Volume Fraction ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Third Order ◽  
Implicit Algorithm ◽  
Proposed Model ◽  
Graded Material ◽  
Composite Modeling

In this work, an implicit algorithm is used for analyzing the free dynamic behavior of Functionally Graded Material (FGM) plates. The Third order Shear Deformation Theory (TSDT) is used to develop the proposed model. In this contribution, the formulation is written without any homogenization technique as the rule of mixture. The Hamilton principle is used to establish the resulting equations of motion. For spatial discretization based on Finite Element Method (FEM), a quadratic element with four and eight nodes is adopted using seven degrees of freedom per node. An implicit algorithm is used for solving the obtained problem. To study the accuracy and the performance of the proposed approach, we present comparisons with literature and laminate composite modeling results for vibration natural frequencies. Otherwise, we examine the influence of the exponent of the volume fraction which reacts the plates "P-FGM" and "S-FGM". In addition, we study the influence of the thickness on "E-FGM" plates.

A System for Three-Dimensional Visualization of Human Jaw Motion in Speech

1997 ◽  
Vol 40 (5) ◽  
pp. 1118-1121 ◽  
Author(s):  
Thierry Guiard-Marigny ◽  
David J. Ostry
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Visual Display ◽  
Visual Speech ◽  
Skeletal Structure ◽  
Visualization System ◽  
Motion Data ◽  
Visual Speech Recognition ◽  
Visualization Software ◽  
Audio Track

With the development of precise three-dimensional motion measurement systems and powerful computers for three-dimensional graphical visualization, it is possible to record and fully reconstruct human jaw motion. In this paper, we describe a visualization system for displaying three-dimensional jaw movements in speech. The system is designed to take as input jaw motion data obtained from one or multi-dimensional recording systems. In the present application, kinematic records of jaw motion were recorded using an optoelectronic measurement system (Optotrak). The corresponding speech signal was recorded using an analog input channel. The three orientation angles and three positions that describe the motion of the jaw as a rigid skeletal structure were derived from the empirical measurements. These six kinematic variables, which in mechanical terms account fully for jaw motion kinematics, act as inputs that drive a real-time three-dimensional animation of a skeletal jaw and upper skull. The visualization software enables the user to view jaw motion from any orientation and to change the viewpoint during the course of an utterance. Selected portions of an utterance may be replayed and the speed of the visual display may be varied. The user may also display, along with the audio track, individual kinematic degrees of freedom or several degrees of freedom in combination. The system is presently being used as an educational tool and for research into audio-visual speech recognition. Interested researchers may obtain the software and source code free of charge from the authors.

scholarly journals Robust Low-Tubal-Rank Tensor Completion via Convex Optimization

2019 ◽  
Author(s):  
Qiang Jiang ◽  
Michael Ng
Keyword(s):  
Degrees Of Freedom ◽  
L1 Norm ◽  
Third Order ◽  
Order Tensor ◽  
Rank Tensor ◽  
Real World Applications ◽  
Algebraic Framework ◽  
Tensor Nuclear Norm ◽  
Theoretical Results ◽  
Weighted Combination

This paper considers the problem of recovering multidimensional array, in particular third-order tensor, from a random subset of its arbitrarily corrupted entries. Our study is based on a recently proposed algebraic framework in which the tensor-SVD is introduced to capture the low-tubal-rank structure in tensor. We analyze the performance of a convex program, which minimizes a weighted combination of the tensor nuclear norm, a convex surrogate for the tensor tubal rank, and the tensor l1 norm. We prove that under certain incoherence conditions, this program can recover the tensor exactly with overwhelming probability, provided that its tubal rank is not too large and that the corruptions are reasonably sparse. The number of required observations is order optimal (up to a logarithm factor) when comparing with the degrees of freedom of the low-tubal-rank tensor. Numerical experiments verify our theoretical results and real-world applications demonstrate the effectiveness of our algorithm.

Postural stability evaluation of the elderly using entropy-based methods

2014 ◽  
Vol 13 (2) ◽  
Author(s):  
B-C. Jiang ◽  
J-S. Shieh ◽  
J-S.Z. Fan ◽  
C-K. Peng
Keyword(s):  
Postural Stability ◽  
The Elderly ◽  
Stability Evaluation

scholarly journals 32 Effect of Dual Task Training Regarding to Postural Stability in the Healthy Elderly

2019 ◽  
Vol 48 (Supplement_4) ◽  
pp. iv9-iv12
Author(s):  
Anyamanee Yingyongyudha ◽  
Thanakorn Ramrong ◽  
Piyatip Yodkue ◽  
Korawit Jamjit ◽  
Pawaris Suchart ◽  
...  
Keyword(s):  
Dual Task ◽  
Postural Stability ◽  
The Elderly ◽  
Postural Instability ◽  
Control Group ◽  
Healthy Elderly ◽  
Before And After ◽  
Task Training ◽  
Dual Task Training ◽  
Experimental Group

Abstract Introduction Postural instability problem in the elderly is associated the cognitive impairment. The ageing process is directly linked to impairments in postural stability. Dual task activity is a commonplace to most activities of daily living. The elderly who has a postural instability and cognitive decline that are mechanisms which lead to an increased risk of falls in the elderly. Objective To investigate the effect of dual task training on postural stability in the healthy elderly. Methods The sixty-six healthy elderly were selected based on the inclusion criteria. With randomized 33 participants in each experimental and control group. The experimental group received dual task training for 6 weeks delivered three days per week. The control group received education for postural stability and aerobic exercise. Their postural stability was assessed using the Mini-BESTest in before and after training. Results The score of the Mini-BESTest compare between before and after 6 weeks were significantly different in postural stability and cognitive from that before in experimental group (p<0.001). Conclusions The finding support the dual task training program can improve postural stability in the elderly. Therefore, the dual task training program should be implemented with the elderly to be a choice of exercises for the elderly with postural instability.

Ranges of postural stability and their changes in the elderly

1994 ◽  
Vol 2 (1) ◽  
pp. 11-17 ◽  
Author(s):  
JW Blaszczyk ◽  
DL Lowe ◽  
PD Hansen
Keyword(s):  
Postural Stability ◽  
The Elderly

scholarly journals Functional Evaluation of Asibot: A New Approach on Portable Robotic System for Disabled People

2012 ◽  
Vol 9 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Alberto Jardón ◽  
Concepción A. Monje ◽  
Carlos Balaguer
Keyword(s):  
Control System ◽  
Degrees Of Freedom ◽  
The Elderly ◽  
Robotic Arm ◽  
Functional Evaluation ◽  
Light Weight ◽  
Disabled People ◽  
New Approach ◽  
Human Care ◽  
Different Levels

In this work, an innovative robotic solution for human care and assistance is presented. Our main objective is to develop a new concept of portable robot able to support the elderly and those people with different levels of disability during the execution of daily tasks, such as washing their face or hands, brushing their teeth, combing their hair, eating, drinking, and bringing objects closer, among others. Our prototype, ASIBOT, is a five degrees of freedom (DOF) self-contained manipulator that includes the control system and electronic equipment on board. The main advantages of the robot are its light weight, about 11 kg for a 1.3 m reach, its autonomy, and its ability to move between different points (docking stations) of the room or from the environment to a wheelchair and vice versa, which facilitates its supportive functions. The functional evaluation of ASIBOT is addressed in this paper. For this purpose the robotic arm is tested in different experiments with disabled people, gathering and discussing the results according to a methodology that allows us to assess users' satisfaction.

scholarly journals The Role of Spinal Orthoses in Osteoporotic Vertebral Fractures of the Elderly Population (Age 60 Years or Older): Systematic Review

2020 ◽  
pp. 219256822094803
Author(s):  
Barry Ting Sheen Kweh ◽  
Hui Qing Lee ◽  
Terence Tan ◽  
Joost Rutges ◽  
Travis Marion ◽  
...  
Keyword(s):  
Systematic Review ◽  
Elderly Patients ◽  
Vertebral Fractures ◽  
Postural Stability ◽  
Elderly Population ◽  
The Elderly ◽  
Functional Improvement ◽  
Osteoporotic Vertebral Fractures ◽  
Spinal Orthoses

Study Design: Systematic review. Objective: Spinal orthoses have been generally used in the management of osteoporotic vertebral fractures in the elderly population with purported positive biomechanical and functional effects. To our knowledge, this is the first systematic review of the literature examining the role of spinal orthoses in osteoporotic elderly patients who sustain low energy trauma vertebral fractures. Methods: A systematic literature review adherent to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. Methodical searches utilizing MEDLINE, EMBASE, Google Scholar, and Cochrane Databases was performed. Results: Of the 2019 articles initially retrieved, 7 published articles (4 randomized controlled trials and 3 prospective cohort studies) satisfied the inclusion criteria. Five studies reported improvement in quantitative measurements of spinal column stability when either a rigid or semirigid orthosis was used, while 1 study was equivocal. The studies also showed the translation of biomechanical benefit into significant functional improvement as manifested by improved postural stability and reduced body sway. Subjective improvement in pain scores and quality of life was also noted with bracing. Conclusion: The use of spinal orthoses in neurologically intact elderly patients aged 60 years and older with osteoporotic compression vertebral fractures results in improved biomechanical vertebral stability, reduced kyphotic deformity, enhanced postural stability, greater muscular strength and superior functional outcomes.

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