Optimising Ankle Foot Orthoses for children with Cerebral Palsy walking with excessive knee flexion to improve their mobility and participation; protocol of the AFO-CP study

Abstract

BackgroundAnkle-Foot-Orthoses with a ventral shell, also known as Floor Reaction Orthoses (FROs), are often used to reduce gait-related problems in children with spastic cerebral palsy (SCP), walking with excessive knee flexion. However, current evidence for the effectiveness (e.g. in terms of walking energy cost) of FROs is both limited and inconclusive. Much of this ambiguity may be due to a mismatch between the FRO ankle stiffness and the patient’s gait deviations.The primary aim of this study is to evaluate the effect of FROs optimised for ankle stiffness on the walking energy cost in children with SCP, compared to walking with shoes alone. In addition, effects on various secondary outcome measures will be evaluated in order to identify possible working mechanisms and potential predictors of FRO treatment success.Method/DesignA pre-post experimental study design will include 32 children with SCP, walking with excessive knee flexion in midstance, recruited from our university hospital and affiliated rehabilitation centres. All participants will receive a newly designed FRO, allowing ankle stiffness to be varied into three configurations by means of a hinge. Gait biomechanics will be assessed for each FRO configuration. The FRO that results in the greatest reduction in knee flexion during the single stance phase will be selected as the subject’s optimal FRO. Subsequently, the effects of wearing this optimal FRO will be evaluated after 12–20 weeks. The primary study parameter will be walking energy cost, with the most important secondary outcomes being intensity of participation, daily activity, walking speed and gait biomechanics.DiscussionThe AFO-CP trial will be the first experimental study to evaluate the effect of individually optimised FROs on mobility and participation. The evaluation will include outcome measures at all levels of the International Classification of Functioning, Disability and Health, providing a unique set of data with which to assess relationships between outcome measures. This will give insights into working mechanisms of FROs and will help to identify predictors of treatment success, both of which will contribute to improving FRO treatment in SCP in term.Trial registrationThis study is registered in the Dutch Trial Register as NTR3418.

Acclimatization of the gait pattern to wearing an ankle–foot orthosis in children with spastic cerebral palsy

“…The data used in this study originates from the AFO-CP trial (Kerkum et al, 2013), which is aimed at optimizing AFO treatment in children with CP. For the present study, data were used from participants who were provided with ventral shell AFOs and evaluated in the gait laboratory directly after the delivery of the AFOs and four weeks later.…”

“…The main inclusion criteria were a confirmed diagnosis of CP and a barefoot gait pattern that was characterized by excessive knee flexion in midstance. Other inclusion criteria have been described elsewhere (Kerkum et al, 2013). Institutional review board approvals were obtained prior to study initiation, and all participants (above 12 years old) and their parents provided written informed consent.…”

Biomechanical Outcomes Related with Gait in Children with Cerebral Palsy Using Ankle-Foot Orthotic - A Systematic Review

“…Spasticity, muscle weakness and decreased selective motor control, often cause limitations in mobility and activities of day living like walking. These limitations, which limit patient's ability to walk [1,3], impact families and -without proper adaptations -may lead to restricted participation in daily life, affecting social relations and education [4,5].…”

“…It is suggested that this system is a commonly intervention in children with CP, and can improve joint stability, posture, and gait skills [6,7]. Therefore, studies have shown that to improve gait and reduce walking limitations, children with CP might use ankle foot orthoses (AFOs) [1,3,4,6,7]. Some studies on the literature evaluating the effects of AFOs on gait in children with CP generally report improvement in gait parameters, like spatiotemporal parameters, joint kinematics and kinetics, and knee extension [3,6].…”

“…As such, AFOs aim to improve, i.e. normalize joint kinetics, joint kinematics and spatiotemporal parameters [4,8].…”