Elsevier

Gait & Posture

Volume 32, Issue 4, October 2010, Pages 436-445
Gait & Posture

Review
The test–retest reliability of centre of pressure measures in bipedal static task conditions – A systematic review of the literature

https://doi.org/10.1016/j.gaitpost.2010.09.012Get rights and content

Abstract

Summary of background data

The analysis of centre of pressure (COP) excursions is used as an index of postural stability in standing. Conflicting data have been reported over the past 20 years regarding the reliability of COP measures and no standard procedure for COP measure use in study design has been established.

Search methods

Six online databases (January 1980 to February 2009) were systematically searched followed by a manual search of retrieved papers.

Results

Thirty-two papers met the inclusion criteria. The majority of the papers (26/32, 81.3%) demonstrated acceptable reliability. While COP mean velocity (mVel) demonstrated variable but generally good reliability throughout the different studies (r = 0.32–0.94), no single measurement of COP appeared significantly more reliable than the others. Regarding data acquisition duration, a minimum of 90 s is required to reach acceptable reliability for most COP parameters. This review further suggests that while eyes closed readings may show slightly higher reliability coefficients, both eyes open and closed setups allow acceptable readings under the described conditions (r  0.75). Also averaging the results of three to five repetitions on firm surface is necessary to obtain acceptable reliability. A sampling frequency of 100 Hz with a cut-off frequency of 10 Hz is also recommended. No final conclusion regarding the feet position could be reached.

Conclusions

The studies reviewed show that bipedal static COP measures may be used as a reliable tool for investigating general postural stability and balance performance under specific conditions. Recommendations for maximizing the reliability of COP data are provided.

Section snippets

Background

Postural stability is an important component in maintaining an upright position and in maintaining balance during normal daily movements and activities. Postural stability is also an important factor in the elderly where balance disability may increase the risk of falls and subsequent injury. In sport, problems with balance may lead to serious injuries [1]. Thus, postural stability has important implications in sports and rehabilitation. Many different methods exist today for assessing postural

Aims

The aims of this systematic literature review are (1) to describe and assess the methodological procedures of studies of the most commonly used COP measurements and methods, (2) to determine the reliability of commonly used centre of pressure measures in bipedal static task conditions, and (3) to provide recommendations regarding standardized COP methods for future use in study designs.

Search strategy

A comprehensive search strategy was developed by identifying all potentially relevant search terms, categorizing these terms into specific search phases and subsequently combining them by using Boolean terms. This search strategy was designed to be used in six different electronic databases. These were PubMed, MEDLINE, EMBASE, Web of Science, ScienceDirect, Digital Dissertations and the Cochrane library. The search strategy is available upon contacting the corresponding author.

Electronic searches

All databases

Literature search results

Initially, the online search strategy identified 215 study abstracts which were screened individually by the reviewers. The application of inclusion/exclusion criteria by the reviewers on the titles and abstracts eliminated a further 162 papers. The most common reason for exclusion was not meeting the selection criteria like static or bipedal tasks. From the titles and abstracts of papers selected (n = 53), full articles were reviewed and the same two reviewers (AR and TB) applied the inclusion

The statistics

As with the general experimental setups, an equally heterogeneous selection of statistics for describing the reliability was used, including the coefficient of variation (CV), generalizability coefficient (GC) as well as Pearson's correlation coefficient (PCC). The most commonly applied statistic however, were the different forms of the intraclass correlation coefficient (ICC). While most used models described originally by Shrout and Fleiss [13], others again employed modified versions [14].

Relationships between methods and reliability

While various studies have investigated the same COP parameters such as mean velocity or area of sway, an inter-study comparison of each parameter's individual reliability is often problematic because of differences in study designs. Only a few studies offer similar experimental procedures that allow for comparing the effect of various factors on the reliability of COP measures (Table 3a, Table 3b, Table 3c).

General considerations

Due to the heterogeneous study designs and statistical models used there remains little common ground for combining the reliability of all data presented. Only a few papers allowed for direct inter-study comparison of results and most of the conclusions had to be drawn from those studies. No quantitative pooling of results from the studies was possible, but we were nevertheless able to extract enough information to make recommendations regarding reliable experimental setups for COP measurements.

Conclusion

The overall results indicate that the reliability of traditional COP parameters is acceptable if our recommendations are followed in the study design. The test–retest reliability depends primarily on factors such as the number of trial recordings and duration rather than the selection of particular COP parameters. Care should be taken to thoroughly assess the subject's physical status and anthropometric properties prior to the measurements. The primary finding of this systematic review is there

Acknowledgements

The author(s) like to thank Tino Bos DC (TB) for his valuable contribution during the first phase of the literature search and Alexander Steinbrenner DC (AS) for volunteering as a third reviewer.

Conflict of interest statement: The authors disclose any financial and personal relationships with other people or organizations that could inappropriately influence (bias) this work.

References (52)

  • R.J. Doyle et al.

    Generalizability of Stabilogram diffusion analysis of center of pressure measures

    Gait Posture

    (2008)
  • B.R. Santos et al.

    Reliability of centre of pressure summary measures of postural steadiness in healthy young adults

    Gait Posture

    (2008)
  • R. Letz et al.

    Standing steadiness measurements: empirical selection of testing protocol and outcome measures

    Neurotoxicol Teratol

    (1995)
  • D. Lafond et al.

    Intrasession reliability of center of pressure measures of postural steadiness in healthy elderly people

    Arch Phys Med Rehabil

    (2004)
  • L. Chiari et al.

    Stabilometric parameters are affected by anthropometry and foot placement

    Clin Biomech (Bristol, Avon)

    (2002)
  • M. Salavati et al.

    Test–retest reliability of center of pressure measures of postural stability during quiet standing in a group with musculoskeletal disorders consisting of low back pain, anterior cruciate ligament injury and functional ankle instability

    Gait Posture

    (2009)
  • O. Hue et al.

    Body weight is a strong predictor of postural stability

    Gait Posture

    (2007)
  • M.J. O’Malley

    Normalization of temporal-distance parameters in pediatric gait

    J Biomech

    (1996)
  • N. Pinsault et al.

    Test–retest reliability of centre of foot pressure measures to assess postural control during unperturbed stance

    Med Eng Phys

    (2009)
  • J.A. Raymakers et al.

    The assessment of body sway and the choice of the stability parameter(s)

    Gait Posture

    (2005)
  • M. Zok et al.

    Should the instructions issued to the subject in traditional static posturography be standardised?

    Med Eng Phys

    (2008)
  • M. Schmid et al.

    The sensitivity of posturographic parameters to acquisition settings

    Med Eng Phys

    (2002)
  • L. Chiari et al.

    An improved technique for the extraction of stochastic parameters from stabilograms

    Gait Posture

    (2000)
  • R.J. Doyle et al.

    Generalizability of center of pressure measures of quiet standing

    Gait Posture

    (2007)
  • M.L. Harringe et al.

    Postural control measured as the center of pressure excursion in young female gymnasts with low back pain or lower extremity injury

    Gait Posture

    (2008)
  • J.W. Blaszczyk et al.

    Effect of ageing and vision on limb load asymmetry during quiet stance

    J Biomech

    (2000)
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