title: An individual approach for optimizing ankle-foot orthoses to improve mobility in children with spastic cerebral palsy walking with excessive knee flexion.
abstract: Ankle-Foot Orthoses (AFOs) are commonly prescribed to promote gait in children with cerebral palsy (CP). The AFO prescription process is however largely dependent on clinical experience, resulting in confusing results regarding treatment efficacy. To maximize efficacy, the AFO's mechanical properties should be tuned to the patient's underlying impairments. This study aimed to investigate whether the efficacy of a ventral shell AFO (vAFO) to reduce knee flexion and walking energy cost could be improved by individually optimizing AFO stiffness in children with CP walking with excessive knee flexion. Secondarily, the effect of the optimized vAFO on daily walking activity was investigated. Fifteen children with spastic CP were prescribed with a hinged vAFO with adjustable stiffness. Effects of a rigid, stiff, and flexible setting on knee angle and the net energy cost (EC) [Jkg(-1)m(-1)] were assessed to individually select the optimal stiffness. After three months, net EC, daily walking activity [stridesmin(-1)] and knee angle [deg] while walking with the optimized vAFO were compared to walking with shoes-only. A near significant 9% (p=0.077) decrease in net EC (-0.5Jkg(-1)m(-1)) was found for walking with the optimized vAFO compared to shoes-only. Daily activity remained unchanged. Knee flexion in stance was reduced by 2.4° (p=0.006). These results show that children with CP who walk with excessive knee flexion show a small, but significant reduction of knee flexion in stance as a result of wearing individually optimized vAFOs. Data suggest that this also improves gait efficiency for which an individual approach to AFO prescription is emphasized.
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: yvettekerkum@gmail.com.
authors.forename: Yvette L
authors.initials: YL
authors.lastname: Kerkum
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Jaap
authors.initials: J
authors.lastname: Harlaar
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Annemieke I
authors.initials: AI
authors.lastname: Buizer
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Josien C
authors.initials: JC
authors.lastname: van den Noort
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Jules G
authors.initials: JG
authors.lastname: Becher
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands; Department of Rehabilitation, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Merel-Anne
authors.initials: MA
authors.lastname: Brehm
mesh_terms: D000842:Ankle; D001696:Biomechanical Phenomena; D002547:Cerebral Palsy; D002648:Child; D061826:Foot Orthoses; D005684:Gait; D006801:Humans; D009989:Orthotic Devices; D016138:Walking
keywords: Daily walking activity; Gait biomechanics; Gait efficiency; Lower limb orthotics