Assessment of seated postural control in children: comparison of a force platform versus a pressure mapping system.

Abstract

To establish the validity and reliability of a pressure mapping system to measure seated postural control in children. A concurrent validity and reliability study. Gait and posture laboratory of a rehabilitation center. Thirteen able-bodied children volunteers. Measurements were taken on a seating simulator in quiet sitting and while reaching. The localization of the center of pressure (COP) in the anteroposterior and mediolateral directions was measured simultaneously by means of a pressure mapping system and a force platform. Concurrent validity was first assessed by Pearson and Spearman correlation coefficients and then by Student paired t tests and Wilcoxon signed-rank test (P<.05) on the range and root mean square (RMS) amplitudes of COP. Reliability was evaluated using intraclass correlation coefficients and coefficients of variation. The COP signals were significantly correlated between both instruments for the RMS and range in both tasks and directions (mean r> or =.87) and for the time series while reaching (r> or =.99), as well as during quiet sitting (r> or =65). Both instruments showed generally fair to good reliability in quiet sitting and excellent reliability when reaching. The pressure mapping system can detect the COP displacement as effectively as the force platform. In a clinical context, it could help in the evaluation of seated stability and also help in evaluating the efficacy of seating components for wheelchair users.