Effects of ankle-foot orthoses on different gait patterns in children with spastic cerebral palsy: A statistical parametric mapping study

Abstract

Background: Ankle-foot orthoses (AFOs) are a common treatment to correct gait deviations in children with spastic cerebral palsy (SCP). Studies on the outcome of AFOs on gait often do not account for different gait patterns. Objectives: The aim of this study was to investigate the effects of AFOs on specific gait patterns in children with cerebral palsy. Study Design: Retrospective, unblinded, controlled, cross-over study. Methods: Twenty-seven children with SCP were assessed in the conditions walking barefoot or with shoes and AFO. AFOs were prescribed based on usual clinical practice. Gait patterns for each leg were classified as excess ankle plantarflexion in stance (equinus), excess knee extension in stance (hyperextension), or excess knee flexion in stance (crouch). Differences in spatial-temporal variables and sagittal kinematics and kinetics of the hip, knee, and ankle between the 2 conditions were determined using paired t-tests and statistical parametric mapping, respectively. The effect of AFO-footwear neutral angle on knee flexion was tested using statistical parametric mapping regression. Results: AFO use improved spatial-temporal variables and reduced ankle power generation in preswing. For “equinus” and “hyperextension” gait patterns, AFOs decreased ankle plantarflexion in preswing and initial swing and decreased ankle power in preswing. Ankle dorsiflexion moment increased in all gait pattern groups. Knee and hip variables did not change in any of the 3 groups. AFO-footwear neutral angle had no effect on changes in sagittal knee angle. Conclusion: Although improvements in spatial-temporal variables were seen, gait deviations could only partially be corrected. Therefore, AFO prescriptions and design should individually address specific gait deviations and their effectiveness in children with SCP should be controlled.