Comparison of center-of-pressure displacement during sit-to-stand according to chair height in children with cerebral palsy.

Abstract

[Purpose] In patients with cerebral palsy (CP), performance of the sit-to-stand (STS) task is influenced by an asymmetrical motor pattern. The purpose of this study was to analyze the effects of an elevated chair on STS performance in patients with CP. [Subjects and Methods] Nine CP patients performed STS from a height-adjustable instrumented chair at their natural speed, with the ankle at a 90° angle to the floor. The center-of-pressure (COP) displacement was recorded under the feet. Each foot position was tested at two chair heights corresponding to 100% and 120% of the leg length. The extent and speed of COP were calculated. [Results] The anteroposterior speed and extent of COP were greater with the standard chair than with the elevated chair. The other parameters such as mediolateral speed, extent, and vertical speed of the COP were not different between the two chairs. [Conclusion] These findings suggest that the sway with STS performed from the elevated chair was lesser than that with STS performed from the standard chair. This information will be relevant to clinicians involved in the rehabilitation of CP patients and will help identify factors that influence STS performance.