Functional Task Constraints Foster Enhanced Postural Control in Children With Cerebral Palsy

Jennifer M. Schmit; Michael Riley; Sarah Cummins-Sebree; Laura Schmitt; Kevin Shockley

doi:10.2522/ptj.20140425

Figures

Figure 1.

Study procedure. Study participants completed a functional play aiming task while postural sway data were collected from a force platform.

Figure 2.

Standard deviation (SD) and 95% confidence interval for the center of pressure (COP) in the functional play task analysis. Significant main effects of task and group in the mediolateral (ML) plane (top) and anteroposterior (AP) plane (bottom) and a significant group × task interaction in the ML plane (top) were observed. During precision-task performance, sway variability decreased in children with cerebral palsy (CP) but not in peers with typical development (TD). Significant group differences that existed during no-task conditions were mitigated during precision-task performance.

Figure 3.

Standard deviation (SD) and 95% confidence interval for the center of pressure (COP) in the difficulty analysis. Significant group effects in the mediolateral (ML) plane (top) and anteroposterior (AP) plane (bottom), a significant difficulty effect in the ML plane (top), and a significant group × difficulty interaction in the ML plane (top) were observed. Children with typical development (TD) demonstrated less sway variability during hard conditions. Sway variability for children with cerebral palsy (CP) was not altered as a function of task difficulty. Significant TD and CP group differences were detected only during hard conditions.

Figure 4.

Sample entropy (SampEn) and 95% confidence interval for the center of pressure (COP) in the functional play task analysis. Significant main effects of task and group in the mediolateral (ML) plane (top) and anteroposterior (AP) plane (bottom) and significant group × task interactions in the ML plane (top) and the AP plane (bottom) were seen. Relative to those in no-task conditions, SampEn values decreased (became more regular) during performance of the precision task in both children with cerebral palsy (CP) and peers with typical development (TD). Group differences in no-task conditions remained significant but were mitigated during precision-task performance.

Figure 5.

Sample entropy (SampEn) and 95% confidence interval for the center of pressure (COP) in the difficulty analysis. Significant group × task interactions in the mediolateral (ML) plane (top) and anteroposterior (AP) plane (bottom) were observed. SampEn values were higher (more irregular) in children with cerebral palsy (CP) than in peers with typical development (TD) regardless of precision-task difficulty.