Related Experiment Video
Updated: May 22, 2026
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Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb
Published on: August 30, 2016
Testing single and double limb standing balance performance: comparison of COP path length evaluation between two
Lars Donath1, Ralf Roth, Lukas Zahner
1Institute of Exercise and Health Sciences, University of Basel, Birsstrasse 320B, CH-4052 Basel, Switzerland. lars.donath@unibas.ch
Gait & Posture
|May 9, 2012
Summary
The GKS balance system shows higher center of pressure (COP) path length readings than the Kistler force platform, with significant random variability. These postural sway measurements are not interchangeable.
Area of Science:
- Biomechanics
- Human Movement Science
- Sports Technology
Background:
- Center of pressure (COP) path length is a standard measure for postural sway, typically using force plates.
- Investigating alternative, cost-effective systems for postural sway analysis is crucial for broader accessibility.
Purpose of the Study:
- To comparatively analyze the GKS balance system against the gold-standard Kistler force platform for COP path length measurements.
- To assess the feasibility and reliability of the GKS system for evaluating postural sway in active adults.
Main Methods:
- 34 active adults were tested on both GKS and Kistler devices during various stance conditions (double/single limb, eyes open/closed).
- COP path length was recorded over 30-second and 10-second intervals.
- Statistical analyses included repeated measures ANOVA, Bland-Altman analysis, and intraclass correlation coefficients (ICC).
Main Results:
- The GKS system consistently yielded higher COP path length values compared to the Kistler platform (p<0.01).
- Significant random variability was observed between the two devices, ranging from 29% to 67%.
- Moderate ICC values (0.57 for 30s, 0.65 for 10s) indicated fair agreement, but large effect sizes highlight task-dependent differences.
Conclusions:
- COP path length measurements from the GKS balance system exhibit considerable random variability and differ significantly from Kistler force platform data.
- The GKS and Kistler systems' postural sway measurements should not be used interchangeably due to observed discrepancies.
- Further methodological research is recommended to validate balance measures from different systems.
