Asymmetry in children with unilateral cerebral palsy during sit-to-stand movement: Cross-sectional, repeated-measures and comparative study

Abstract

BackgroundWe aimed to compare motor strategies adopted by children with unilateral Cerebral Palsy and typically developing children during the performance of sit-to-stand. MethodsEleven children with unilateral cerebral palsy and 20 typically developing children were evaluated. Kinematic and kinetic analysis of the sit-to-stand movement was performed. Three seat heights were evaluated: neutral (90° of hip-knee-ankle flexion), elevated to 120% of the neutral height, and lowered to 80% of the neutral height. As outcome variables, we considered sit-to-stand duration (temporal); initial, final and maximal sagittal angles and range of motion of trunk, pelvis, hip, knee, and ankle (kinematics); the peak of vertical ground reaction force (kinetics), and asymmetric index. Effect size is represented by η2p. FindingsWe found that for the lowered seat, all groups presented increased flexion of lower limbs and trunk to initiate sit-to-stand (p≤0.012; η2p = 0.41–0.84), increased peak flexion of trunk, hip and knee (p≤0.01; η2p = 0.39–0.88), increased range of motion of knee and trunk (p≤0.01; η2p = 0.45–0.85) and the duration of sit-to-stand (p≤0.05 η2p = 0.23–0.56). Children with unilateral cerebral palsy presented increased posterior pelvic tilt (p≤0.01) and decreased hip flexion of both lower limbs (p≤0.01) for all seat heights and moved their non-affected limb backward in the lowered seat (p≤0.01). Asymmetry was observed for the final and the maximal angles of the ankle in neutral and lowered seats in unilateral cerebral palsy (asymmetry index = 3.3–5.8%). InterpretationThe lowered seat height led to adaptive motor strategies in children with unilateral cerebral palsy, which should be considered in clinical practice.