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

<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>

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

Journal of Healthcare Engineering ◽

10.1155/2018/2818063 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

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.

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Volume of confidence ellipsoid: a technique for quantifying trunk sway during stance

Biomedical Engineering / Biomedizinische Technik ◽

10.1515/bmt-2014-0012 ◽

2015 ◽

Vol 60 (2) ◽

Cited By ~ 5

Author(s):

Patrik Kutilek ◽

Ondrej Cakrt ◽

Vladimir Socha ◽

Karel Hana

Keyword(s):

Healthy Subjects ◽

Three Dimensional ◽

Principal Component ◽

Eyes Closed ◽

Trunk Sway ◽

Eyes Open ◽

Ellipsoid Volume ◽

Three Degree Of Freedom ◽

Balance Problems ◽

Confidence Ellipsoid

AbstractThe position of the trunk can be negatively affected by many diseases. This work focuses on a noninvasive method of quantifying human postural stability and identifying defects in balance and coordination as a result of the nervous system pathology. We used a three-degree-of-freedom orientation tracker (Xsens MTx unit) placed on a patient’s trunk and measured three-dimensional (3-D) data (pitch, roll, and yaw) during quiet stance. The principal component analysis was used to analyze the data and to determine the volume of 3-D 95% confidence ellipsoid. Using this method, we were able to model the distribution of the measured 3-D data (pitch, roll, and yaw). Eight patients with degenerative cerebellar disease and eight healthy subjects in this study were measured during stance, with eyes open and eyes closed, and statistical analysis was performed. The results of the new method based on the 3-D confidence ellipsoid show that the volumes related to the patients are significantly larger than the volumes related to the healthy subjects. The concept of confidence ellipsoid volume, although known to the biomechanics community, has not been used before to study the postural balance problems. The method can also be used to study, for example, head and pelvis movements or alignments during stance.

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

Volume 3: Biomedical and Biotechnology Engineering ◽

10.1115/imece2018-87585 ◽

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.

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

Hip International ◽

10.5301/hipint.5000395 ◽

2016 ◽

Vol 26 (6) ◽

pp. 567-572 ◽

Cited By ~ 7

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.

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Test–retest reliability for assessment of postural stability using center of pressure spatial patterns of three-dimensional statokinesigrams in young health participants

Journal of Biomechanics ◽

10.1016/j.jbiomech.2014.07.010 ◽

2014 ◽

Vol 47 (12) ◽

pp. 2919-2924 ◽

Cited By ~ 12

Author(s):

Arthur de Sá Ferreira ◽

Patrícia Junqueira Ferraz Baracat

Keyword(s):

Spatial Patterns ◽

Postural Stability ◽

Center Of Pressure ◽

Three Dimensional ◽

Retest Reliability ◽

Test Retest Reliability

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Analysis of three-dimensional endocardial and epicardial strains from cardiac magnetic resonance in healthy subjects and patients with hypertrophic cardiomyopathy

Medical & Biological Engineering & Computing ◽

10.1007/s11517-017-1674-2 ◽

2017 ◽

Vol 56 (1) ◽

pp. 159-172 ◽

Cited By ~ 3

Author(s):

Xiaodan Zhao ◽

Ru San Tan ◽

Hak Chiaw Tang ◽

Shuang Leng ◽

Jun-Mei Zhang ◽

...

Keyword(s):

Cardiac Magnetic Resonance ◽

Hypertrophic Cardiomyopathy ◽

Magnetic Resonance ◽

Healthy Subjects ◽

Three Dimensional

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Losing touch: age-related changes in plantar skin sensitivity, lower limb cutaneous reflex strength, and postural stability in older adults

Journal of Neurophysiology ◽

10.1152/jn.00339.2016 ◽

2016 ◽

Vol 116 (4) ◽

pp. 1848-1858 ◽

Cited By ~ 17

Author(s):

Ryan M. Peters ◽

Monica D. McKeown ◽

Mark G. Carpenter ◽

J. Timothy Inglis

Keyword(s):

Older Adults ◽

Lower Limb ◽

Postural Stability ◽

Tibialis Anterior ◽

Tibialis Anterior Muscle ◽

Quiet Standing ◽

Detection Thresholds ◽

Cutaneous Reflex ◽

Age Related ◽

Age Related Changes

Age-related changes in the density, morphology, and physiology of plantar cutaneous receptors negatively impact the quality and quantity of balance-relevant information arising from the foot soles. Plantar perceptual sensitivity declines with age and may predict postural instability; however, alteration in lower limb cutaneous reflex strength may also explain greater instability in older adults and has yet to be investigated. We replicated the age-related decline in sensitivity by assessing monofilament and vibrotactile (30 and 250 Hz) detection thresholds near the first metatarsal head bilaterally in healthy young and older adults. We additionally applied continuous 30- and 250-Hz vibration to drive mechanically evoked reflex responses in the tibialis anterior muscle, measured via surface electromyography. To investigate potential relationships between plantar sensitivity, cutaneous reflex strength, and postural stability, we performed posturography in subjects during quiet standing without vision. Anteroposterior and mediolateral postural stability decreased with age, and increases in postural sway amplitude and frequency were significantly correlated with increases in plantar detection thresholds. With 30-Hz vibration, cutaneous reflexes were observed in 95% of young adults but in only 53% of older adults, and reflex gain, coherence, and cumulant density at 30 Hz were lower in older adults. Reflexes were not observed with 250-Hz vibration, suggesting this high-frequency cutaneous input is filtered out by motoneurons innervating tibialis anterior. Our findings have important implications for assessing the risk of balance impairment in older adults.

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Assessment of postural stability using the Zebris Platform in women above the age of 60

Journal of Kinesiology and Exercise Sciences ◽

10.5604/01.3001.0014.8210 ◽

2020 ◽

Vol 30 (92) ◽

pp. 13-18

Author(s):

Janusz Jaworski ◽

Ewelina Kołodziej

Keyword(s):

Physical Activity ◽

Comparative Analysis ◽

Postural Stability ◽

Balance Control ◽

Regular Physical Activity ◽

Foot Pressure ◽

Stability Parameters ◽

Younger Women ◽

Centre Of Foot Pressure ◽

Ellipse Area

Introduction. Balance control and body posture stability disorders progressing with age are caused by the involutionary changes in the function of the motor and nervous systems. However, it is indicated that regular physical activity, also in older adulthood, may have a positive effect on maintaining the functions of individual systems at an optimal level. Study aim: The aim of the study was to assess the postural stability of women above the age of 60 who declare active lifestyles. Material and Methods. The research involved 24 women, who were arbitrarily divided into 3 groups according to their calendar age. The younger group consisted of 14 women below the age of 70 years ( x _ = 65.08; SD = 2.82), whereas the older group comprised 10 older adults, above the age of 70 ( x _ = 73.62; SD = 2.74). The scope of the study included evaluation of selected postural stability parameters: 95% of the ellipse area covered by the moving COP, statokinesiogram path length, mean speed regarding displacement of the centre of foot pressure, total left and total right foot pressure. The examinations were performed in June 2018 using the Zerbis FDM-S dynamographic platform. The research material collected in this way was subjected to statistical analysis. Basic descriptive statistics were calculated and normality of the distribution of variables was verified using the Shapiro- Wilk test. The Student’s t-test for independent variables or Mann-Whitney’s U-test (depending on the distribution) were used to determine the significance of differences concerning the analysed parameters of postural stability between the groups studied. Furthermore, for 95% of the ellipse area covered by the moving COP, statokinesiogram path and mean speed of the displacement of the centre of foot pressure and standardised profiles were calculated for both chronological age groups. Standardisation of the results was performed using means and standard deviations of the entire material (T scale). Results. The results of the study indicate a higher level of postural stability among women from the younger group. However, comparative analysis did not reveal any statistically significant intergroup differences. Mean point scores on the T scale in the group of younger women for the 3 variables ranged from 50.98 to 51.60 points, whereas for older women, this was from 48.90 to 48.98 points. The differences between characteristics in the group of younger women totalled ca. 0.62 points, while in the older group, this value was 0.08 points. Conclusions. comparative analysis allowed to show that postural stability indices in women above 70 decreased compared to the results obtained for the younger group. Regular physical activity may be one of the significant factors in the prevention of postural stability regression.

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