Measurement of the visual contribution to postural steadiness from the COP movement: methodology and reliability

Cornilleau-Pérès, V.; Shabana, Noor; Droulez, Jacques; Goh, James Cho Hong; Lee, G.S.M.; Chew, Peter

doi:10.1016/j.gaitpost.2004.07.009

Cited by 92 publications

(69 citation statements)

References 36 publications

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“…What is more, as taking the derivative of a signal (velocity and acceleration) attenuates lower frequency components and amplifies higher frequency components of a signal, a higher sampling rate is necessary to reproduce the signal [18]. For this, we propose to increase the sampling rate to 100 Hz in agreement with previous authors as [19] and then to filter COP signals with a low-pass filter before calculating velocity and acceleration. This will decrease the sensitivity to noise ratio by which the numerical derivatives are easily affected.…”

Section: Discussionmentioning

confidence: 95%

Expanded Disability Status Scale (EDSS) estimation in multiple sclerosis from posturographic data

et al. 2013

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Expanded disability status scale (EDSS) is the most widely used clinical scale to evaluate levels of multiple sclerosis (MS). As MS can lead to disruptions in the regulation of balance and the disability can be evaluated by force platform posturography, we have developed in this study a new strategy to estimate EDSS from postural data. 118 volunteers with EDSS ranging from 0 to 4.5 participated in this study, with eyes closed. By using second-order polynomial regression models, EDSS was estimated from two postural sway parameters, respectively, the length and the surface and four recurrence quantification analysis (RQA) parameters: percentage of recurrence (%Rec), Shannon entropy (Ent), mean diagonal line length (LL) and trapping time (TT). In addition, all four RQA parameters were calculated for position, instantaneous velocity and acceleration of the center of pressure. In order to select the most accurate method for estimating EDSS, four statistical indices (percentage of agreement, underestimation and overestimation, as well as mean error) were calculated comparing clinical and estimated EDSS scores. The results demonstrate that estimations of EDSS from surface, %Rec and LL of position, best agreed with clinical scores. This study emphasizes the possibility of distinguishing EDSS scores using postural sway and RQA parameters.

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Section: Discussionmentioning

confidence: 95%

Expanded Disability Status Scale (EDSS) estimation in multiple sclerosis from posturographic data

et al. 2013

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“…For each direction (AP and ML), the mean, range and root mean square (RMS) values of the COP displacements were calculated according to Cornilleau-Pérès et al [14]. In standing balance, forces acting at the centre of pressure control the centre of mass excursion at any given moment.…”

Section: Methodsmentioning

confidence: 99%

Free moment contribution to quiet standing in able-bodied and scoliotic girls

et al. 2007

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Adolescent idiopathic scoliosis girls are known to display standing imbalance. In addition to a motor deficit problem, the axial torsion of the spine and trunk torsion could reflect an imbalance around the vertical axis. Unlike the excursion of the center of pressure (COP), the forces and moments were rarely addressed to characterize the quiet standing balance. Nonetheless, one dynamical parameter, called free moment (T V ), representing the vertical torque on the feet can reflect the oscillation around the vertical axis associated to the standing imbalance. The objectives of this study were to test if the free moment variability can be utilized to characterize standing balance in a group of able-bodied and non-treated scoliotic girls and to determine if it was associated with that of the COP among each group of subjects tested. Forty-six adolescent girls with half of them presenting an adolescent idiopathic scoliosis were tested during quiet standing balance.Standing balance was assessed with the subjects standing upright and bare feet on a force plate. RMS and range of COP excursions and free moment were calculated.The scoliotic group displayed higher variability in COP excursion by about 24% than the able-bodied girls. Similarly, the T V RMS (P = 0.00136) and range (P = 0.00197) were statistically higher by about 42% in the scoliotic group. The variability of T V was associated with that of the COP in both groups. In the medio-lateral direction, the significant correlations between the RMS and range of the free moment and those of the COP were about 0.7 for the able-bodied group and 0.5 for the medio-lateral COP range for the scoliotic group girls. Along the antero-posterior axis, the only statistically significant correlations were observed for the scoliotic group. The free moment variability about the COP measured during quiet standing can be suggestive of an asymmetry control of the trunk around the vertical axis during standing balance. Its variability was more pronounced in scoliotic girls and was associated with the antero-posterior COP variability reflecting both biomechanical and motor control deficits. Free moment calculation could be a supplement insight into the standing balance of scoliotic subjects. Keywords Scoliosis Á Standing balance Á Free moment Abbreviations APAntero-posterior direction COM The center of mass is a point equivalent of the total body mass resulting from the location of each body segment COP The center of pressure is the location of the net ground reaction force. ML Medio-lateral direction x where X m is the arithmetic mean of the variable X. X i is the ith value of the variable X measured at the instant i, and N is the number of X i values

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“…Two of them are from the global analysis, the CP trajectory and the frequency band of the stabilogram, and the other two are from a structural analysis proposed by them 35 . However, among the measures used, the mean velocity of the CP has been considered the measure with the highest reliability among trials 1,36 . On the other hand, Doyle, Newton and Burnett 37 reported that the variables' peak velocity and sway area have shown, respectively, the highest and the lowest levels of reliability.…”

Section: Analysis and Interpretation Of The Cp Characteristicsmentioning

confidence: 99%

Revisão sobre posturografia baseada em plataforma de força para avaliação do equilíbrio

Duarte¹,

Freitas²

2010

Rev. bras. fisioter.

510

195

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Measurement of the visual contribution to postural steadiness from the COP movement: methodology and reliability

Cited by 92 publications

References 36 publications

Expanded Disability Status Scale (EDSS) estimation in multiple sclerosis from posturographic data

Expanded Disability Status Scale (EDSS) estimation in multiple sclerosis from posturographic data

Free moment contribution to quiet standing in able-bodied and scoliotic girls

Revisão sobre posturografia baseada em plataforma de força para avaliação do equilíbrio

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