Postural adjustment of children with spastic diplegic cerebral palsy during seated hand reaching in different directions

Objectives: To examine the effect of reaching in different directions on postural adjustment in children with diplegic cerebral palsy (CP), and to examine the relationship between hand reach performance and postural adjustment, and between postural control ability and postural adjustment. Design: Cross-sectional study. Setting: A movement science laboratory at a medical university. Participants: Children with CP (n=12) and typically developing (TD) children (n=16). Interventions: Not applicable. Main Outcome Measures: Two force platforms were used to measure the ground reaction force (GRF) and center of pressure (COP) data. Absolute peak COP velocity, COP sway ratio (SR), and mean GRF in the anterior posterior direction during the acceleration and deceleration segments of a reaching task were the main outcome measures. Results: Children with CP showed a greater absolute peak COP velocity in the medial lateral direction, a smaller SR (wider COP pattern), and greater amplitude of force modulation (exaggerated postural adjustments) than TD children in lateral or medial reaches. There was a moderate correlation between SR and total Pediatric Reach Test score. The chair SR was also negatively correlated with the hand movement units. Conclusions: Children with CP showed wider, more crooked, and less efficient COP patterns than TD children, especially on medial or lateral reaches. Reaching medially or laterally involves trunk rotation, which produces more postural challenges than reaching anteriorly to children with CP. The patterns of postural adjustments in children with CP were correlated with their postural control ability and hand-reach smoothness.