Reliability of Force-Platform Measures of Postural Sway and Expertise-Related Differences

2011 ◽  
Vol 20 (4) ◽  
pp. 442-456 ◽  
Author(s):  
Zohreh Meshkati ◽  
Mehdi Namazizadeh ◽  
Mahyar Salavati ◽  
Masood Mazaheri

Context:Although reliability is a population-specific property, few studies have investigated the measurement error associated with force-platform parameters in athletic populations.Objective:To investigate the skill-related differences between athletes and nonathletes in reliability of center-of-pressure (COP) summary measures under eyes-open (EO) and eyes-closed (EC) conditions.Design:Test–retest reliability study.Setting:COP was recorded during double-leg quiet standing on a Kistler force platform before and after a fatiguing treadmill exercise, with EO and EC.Participants:31 male participants including 15 athletes practiced in karate and 16 nonathletes.Main Outcome Measures:Standard deviation (SD) of amplitude, phase-plane portrait, SD of velocity, mean total velocity, and area were calculated from 30-s COP data. Intraclass correlation coefficient (ICC), standard error of measurement, and coefficient of variation (CV) were used as estimates of reliability and precision.Results:Higher ICCs were found for COP measures in the athlete (compared with the nonathlete) group, postfatigued (compared with prefatigued) condition, and EC (compared with EO) tests. CVs smaller than 15% were obtained for most of the COP measures. SD of velocity in the anteroposterior direction showed the highest reliability in most conditions.Conclusions:Tests with EC and to a lesser extent tests performed in the athlete group and in the postfatigued condition showed better reliability.

2020 ◽  
pp. 003151252094509
Author(s):  
Mark Walsh ◽  
Caroline Church ◽  
Audrey Hoffmeister ◽  
Dean Smith ◽  
Joshua Haworth

Measurements of postural sway are used to assess physiological changes due to therapy or sport training, or to describe group differences based on activity history or disease status. Portable force plates have been widely adopted for this purpose, leading us in this study to validate with linear and nonlinear metrics the posturographic data derived from both a portable plate (Natus) when compared to an in-ground plate (Bertec). Twenty participants stood on each plate for two trials each, with and without a foam perturbation and with and without eyes open on each surface. We calculated measures of path length, range, root mean squares, sample entropy, and correlation dimensions from center of pressure traces on each plate. An intraclass correlation coefficient across trials from each plate in each condition indicated satisfactory overall reliability (ICC consistency), supporting the use of either plate for postural sway research and interventions. Additionally, our results generally supported common validity (ICC absolute agreement), though, the specific degree of similarity differed for each of the tested metrics of postural sway, especially when considering whether or not data was filtered. For situations in which participants cannot visit a laboratory (e.g. performing athletes, community dwelling clinical patients, and virus risk concerns) an in-home portable force plate is a trusted and valuable data collection tool.


2004 ◽  
Vol 21 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Eryk P. Przysucha ◽  
M. Jane Taylor

The purpose of this study was to compare the postural sway profiles of 20 boys with and without Developmental Coordination Disorder (DCD) on two conditions of a quiet standing task: eyes open and eyes closed. Anterior-posterior (AP) sway, medio-lateral sway (LAT), area of sway, total path length, and Romberg’s quotient were analyzed. When visual information was available, there was no difference between groups in LAT sway or path length. However, boys with DCD demonstrated more AP sway (p < .01) and greater area of sway (p < .03), which resulted in pronounced excursions closer to their stability limits. Analysis of Romberg’s quotient indicated that boys with DCD did not over-rely on visual information.


2013 ◽  
Vol 29 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Paulo H. Marchetti ◽  
Maria I.V. Orselli ◽  
Marcos Duarte

The aim of this study was to investigate the effects of unilateral and bilateral fatigue on both postural and power bipedal tasks. Ten healthy subjects performed two tasks: bipedal quiet standing and a maximal bipedal counter-movement jumping before and after unilateral (with either the dominant or nondominant lower limb) and bilateral (with both lower limbs) fatigue. We employed two force plates (one under each lower limb) to measure the ground reaction forces and center of pressure produced by subjects during the tasks. To quantify the postural sway during quiet standing, we calculated the resultant center of pressure (COP) speed and COP area of sway, as well as the mean weight distribution between lower limbs. To quantify the performance during the countermovement jumping, we calculated the jump height and the peak force of each lower limb. We observed that both unilateral and bilateral fatigue affected the performance of maximal voluntary jumping and standing tasks and that the effects of unilateral and bilateral fatigue were stronger in the dominant limb than in the nondominant limb during bipedal tasks. We conclude that unilateral neuromuscular fatigue affects both postural and power tasks negatively.


2021 ◽  
Vol 12 ◽  
Author(s):  
Žiga Kozinc ◽  
Nebojša Trajković ◽  
Darjan Smajla ◽  
Nejc Šarabon

Neuromuscular fatigue is known to impair balance ability, which is reflected in increased postural sway during quiet standing tasks. Recently, quantifying transient characteristics of postural sway has been suggested as an approach to obtain additional information regarding postural control. However, this approach is currently vastly unexplored. The purpose of this study was to investigate the effects of fatigue (induced by a repeated change of direction task) on postural sway and its transient characteristics during single-leg standing, including whole-trial estimates and indexes of transient behavior in young healthy active adults. The study involved 28 physically active students (14 females). Single-leg postural sway was recorded for 30s before and after a fatiguing protocol, which consisted of a repeated change of direction tasks. We calculated the traditional whole-trial estimates of postural sway [center-of-pressure (CoP) velocity and amplitude in anterior-posterior (AP) and medial-lateral (ML) directions] and corresponding transient behavior indexes, based on three 10-s intervals. Statistically significant sex×fatigue interaction with medium effect sizes was found for whole-trial CoP velocity in AP (p=0.028; η2=0.17) and ML directions (p=0.019; η2=0.19). Post-hoc test showed that both variables substantially decreased in female participants (p=0.041–0.045; d=0.54–0.56), but remained similar in males (p=0.194–0.294). There were small to medium statistically significant main effects of fatigue on transient index for CoP amplitude in both directions (p=0.042–0.049; η2=0.02–0.14). Notably, CoP AP amplitude increased in the first 10-s interval for males (before fatigue: 5.6±1.3mm; after fatigue: 6.3±1.6mm), while the CoP AP amplitude in the third interval remained similar after fatigue (before fatigue: 5.5±1.4mm; after fatigue: 5.1±1.2mm). In conclusion, the responses to fatigue in terms of postural sway were time interval specific, and there were certain sex-differences in responses to fatigue, which could be related to better ability to adapt balance strategies in females. Moreover, our results demonstrate that the indexes of transient behavior could perhaps detect smaller fatigue-induced changes in postural sway that are seen in whole-trial estimates.


2007 ◽  
Vol 50 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Jitka Jančová ◽  
Vlasta Tošnerová

Posture in a still stance has been quantified by changes in the center of pressure (COP), in both anterior-posterior (A/P) and medial-lateral (M/L) directions and measured on a single force platform (Bertec PRO VEC 5.0). The purpose of this study was to estimate the variance in error and the intrasession test-retest reliability, and to determine which measures shall be taken for further measurements, especially with adults age 65 and older. We used two types of approximation for the reliability coefficient. Firstly, we used the equation according to Blahuš (2) and secondly we used the Pearson’s correlation coefficient for test-retest measurements. The findings allow us to say, among other things, that the tests of quiet standing Double Narrow Stance Eyes Open (DNSEO) and Double Narrow Stance Eyes Closed (DNSEC) are parallel, in the sense of parallel testing.


2014 ◽  
Vol 94 (10) ◽  
pp. 1489-1498 ◽  
Author(s):  
Charlotte M. Hunt ◽  
Gail Widener ◽  
Diane D. Allen

Background People with multiple sclerosis (MS) have diminished postural control, and center of pressure (COP) displacement varies more in this population than in healthy controls. Balance-based torso-weighting (BBTW) can improve clinical balance and mobility in people with MS, and exploration using both linear and nonlinear measures of COP may help determine whether BBTW optimizes movement variability. Objective The aim of this study was to investigate the effects of BBTW on people with MS and healthy controls during quiet standing. Design This was a quasi-experimental study comparing COP variability between groups, between eye closure conditions, and between weighting conditions in the anterior-posterior and medial-lateral directions. Methods Twenty participants with MS and 18 healthy controls stood on a forceplate in 4 conditions: eyes open and closed and with and without BBTW. Linear measures of COP displacement included range and root mean square (RMS). Nonlinear measures included approximate entropy (ApEn) and Lyapunov exponent (LyE). Three-way repeated-measures analyses of variance compared measures across groups and conditions. The association between weighting response and baseline nonlinear variables was examined. When significant associations were found, MS subgroups were created and compared. Results The MS and control groups had significantly different range, RMS, and ApEn values. The eyes-open and eyes-closed conditions had significantly different range and RMS values. Change with weighting correlated with LyE (r=−.70) and ApEn (r=−.59). Two MS subgroups, with low and high baseline LyE values, responded to BBTW in opposite directions, with a significant main effect for weighting condition for the LyE variable in the medial-lateral direction. Limitations The small samples and no identification of impairments related to LyE at baseline were limitations of the study. Conclusions The LyE may help differentiate subgroups who respond differently to BBTW. In both subgroups, LyE values moved toward the average of healthy controls, suggesting that BBTW may help optimize movement variability in people with MS.


1998 ◽  
Vol 7 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Andrew G. Baker ◽  
William G. Webright ◽  
David H. Perrin

The purpose of this study was to examine the effects of a resistive tubing kick training protocol on postural sway in uninjured collegiate wrestlers. An experimental group (n= 10) performed a progressive resistive tubing kick training protocol three times per week for 6 weeks. A control group (n= 9) performed no resistive tubing training during the 6 weeks. Postural sway (stability index) was assessed before and after the 6-week training period. ANOVAs demonstrated no significant interactions, although significant main effects were found for group and eye condition. The experimental group demonstrated less postural sway than the control group regardless of training, and postural sway was greater with the eyes closed than with the eyes open. Resistive tubing kick training does not significantly improve postural sway in healthy collegiate wrestlers. Further research should examine the potential benefits of proprioceptive training using a greater intensity of training and/or using subjects who have a greater potential for improvement.


2021 ◽  
Author(s):  
Jinpeng Lin ◽  
Fang Wang ◽  
Yaqi Zhao ◽  
Junjie Li ◽  
Jixin Li ◽  
...  

Abstract Background: Dynamic balance assessment, which requires a specialized device, is crucial in clinic to evaluate postural control comprehensively. The Nintendo Wii Balance Board (WBB), a portable force platform may be a suitable alternative to the expensive “gold standard”- the laboratory-grade force platform (FP). However, its validity in assessment of dynamic balance is still unclear. The purpose of this study is to demonstrate the validity of the WBB in dynamic balance assessment.Methods: We performed three static and dynamic balance tests, including open eyes single-leg stand, close eyes single-leg stand and Limitation of Stability, on the WBB for 34 healthy participants. Trajectories of center of pressure (COP) were recorded synchronously and used to compute seven characteristics. To quantify the consistency of the two devices, we used intraclass correlation coefficient (ICC) as well as visual evaluation of Bland–Altman plots.Results: The data showed a high consistency between the two devices (ICC = 0.92-0.98) under static and dynamic balance assessments, and the visual evaluation result from Bland–Altman plot was acceptable between device agreement. Moreover, in the dynamic balance task (Limitation of Stability test), the typical ranges of COP-based postural sway distances for healthy adults in medial-lateral and anterior-posterior measured by the WBB were 27.17 ± 3.88 cm and 21.13 ± 2.33 cm, respectively, indicating the validity of the WBB in assessing COP under both static or dynamic balance tasks. Conclusion: With the advantages of portability and low-cost, the valid WBB can facilitate the popularization of quantitative balance evaluation to basic hospitals. Our results provide valuable reference for clinical evaluation of balance ability.


Author(s):  
Francesco Palazzo ◽  
Alessandra Nardi ◽  
Niloofar Lamouchideli ◽  
Alfio Caronti ◽  
Anas Alashram ◽  
...  

AbstractIn previous studies, the influence of plantar sensation has been examined using various textured surfaces with different stiffness materials to assess static balance. This study investigated the effects of a Firm Textured Surface (FTS) along with age and sex-related influences on postural control under different visual conditions. Forty subjects (20 elderly, 10 males, mean age 68.30, 10 females, mean age 68.00, and 20 young people, 10 males, mean age 25.45, 10 females, mean age 27.30) participated in this study maintained a quiet standing on FTS, foam and firm surfaces with eyes open and closed. The center of pressure displacement (CoPDISP), CoP velocity (CoPVEL), and sway velocity of the CoP in anteroposterior (AP) and mediolateral (ML) direction (VA/P and VM/L) were measured. FTS was associated with lower postural sway measures in both the groups with eyes open and closed. However, the foam surface showed the worst results in all postural parameters under all experimental conditions. Separate four-way ANOVAs were applied to each dependent variable. The main effects of surface (p < 0.0001), vision (p < 0.0001) and age (p < 0.0001 for CoPDISP, CoPVEL and VA/P; p = 0.0003 for VM/L) were significant in each of the four fitted models. Sex was never significant, either as a main effect or an interaction with other experimental factors. Eyes open were able to reduce the negative effects of the foam surfaces but without vision the proprioceptive sensory system cues of the body state become more important for maintaining balance. A good stimulation with rigid texture should be considered as relief to reduce the physiological-related decline of afferent information with age.


2020 ◽  
Vol 22 (2) ◽  
Author(s):  
Krzysztof Graff ◽  
Ewa Szczerbik ◽  
Małgorzata Kalinowska ◽  
Maciej Jaworski ◽  
Małgorzata Syczewska

Purpose: The aim of the study was to compare the results of six balance tests collected on AMTI AccuSway Plus ACS force platform between healthy female and male children and adolescents. We also searched for possible correlation of the balance measures with subjects’ age. Methods: 228 healthy 6- to 18-year-old subjects (111 boys and 117 girls) participated in the study. Six balance tests were performed with the use of AMTI AccuSway Plus ACS platform: quiet standing for 30s, maximal voluntary sways of the body in the sagittal plane (anterior-posterior – AP test) for 30 s, and in the frontal plane (left-right – ML test) for 30s. All tests were performed in two conditions: eyes open and eyes closed. Results: During quiet standing with eyes open, most balance measures were lower in girls (p < 0.05). In AP and ML tests with eyes open, a few balance parameters were different between boys and girls (p < 0.05). In quiet standing, AP and ML tests with eyes closed, there were no between-gender differences (p > 0.05). In quiet standing with eyes open and closed most balance parameters were negatively correlated with age (p < 0.05). Conclusions: Quiet standing postural sway characteristics depended on gender under normal visual conditions and it was similar in boys and girls under visual deprivation conditions. The vision was differently used by females and males in balance tasks. Static postural stability improved with age regardless of visual conditions.


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