How can push-off be preserved during use of an ankle foot orthosis in children with hemiplegia? A prospective controlled study

Abstract

Several studies indicated that walking with an ankle foot orthosis (AFO) impaired third rocker. The purpose of this study was to evaluate the effects of two types of orthoses, with similar goal settings, on gait, in a homogeneous group of children, using both barefoot and shoe walking as control conditions. Fifteen children with hemiplegia, aged between 4 and 10 years, received two types of individually tuned AFOs: common posterior leaf-spring (PLS) and Dual Carbon Fiber Spring AFO (CFO) (with carbon fibre at the dorsal part of the orthosis). Both orthoses were expected to prevent plantar flexion, thus improving first rocker, allowing dorsiflexion to improve second rocker, absorbing energy during second rocker, and returning it during the third rocker. The effect of the AFOs was studied using objective gait analysis, including 3D kinematics, and kinetics in four conditions: barefoot, shoes without AFO, and PLS and CFO combined with shoes. Several gait parameters significantly changed in shoe walking compared to barefoot walking (cadence, ankle ROM and velocity, knee shock absorption, and knee angle in swing). The CFO produced a significantly larger ankle ROM and ankle velocity during push-off, and an increased plantar flexion moment and power generation at pre-swing compared to the PLS (<0.01). The results of this study further support the findings of previous studies indicating that orthoses improve specific gait parameters compared to barefoot walking (velocity, step length, first and second ankle rocker, sagittal knee and hip ROM). However, compared to shoes, not all improvements were statistically significant.

How Does Ankle-foot Orthosis Stiffness Affect Gait in Patients With Lower Limb Salvage?

“…These results are also in agreement with footwear literature that reports less knee flexion in soft midsole (ie, more compliant) running shoes [28]. In theory, an AFO with spring-like material properties that stores energy during midstance and returns the maximum amount of energy during late stance/preswing should be most beneficial to the user [3,12,42]. However, Bregman et al [6] undertook a simulation approach to investigate how different stiffnesses affected walking biomechanics and found that the optimal (least metabolic cost) stiffness occurred when hip compensations were minimized.…”

“…The resulting gait is mechanically inefficient [8,22] and leads to elevated energy cost [29,39]. Most passive-dynamic AFOs help compensate by functioning as a spring that stores energy when initially deformed in midstance and returns energy at the end of stance [2,12,42]. The stiffness of a dynamic AFO can be optimized to alleviate gait-related problems [4,18,36] because it determines the extent to which the AFO maintains the ankle in a neutral position, provides mediolateral stability, and aids propulsion through energy storage and return mechanisms [25,36].…”

A Systematic Review to Determine Best Practice Reporting Guidelines for AFO Interventions in Studies Involving Children with Cerebral Palsy

“…7 Several authors have noted variable depth and breadth of detail provided by studies within the body of orthotic literature. 2,3,9 While there are general guidelines for reporting of intervention detail in randomized and non-randomized trials (e.g., the CONSORT statement, 8,10,11 and the TREND statement 12 ), there are currently no guidelines recommending the specific detail that should be reported in AFO intervention studies. This is thus the first review to focus specifically on the level and quality of detail reported by AFO intervention studies on children with CP, about the participant samples, AFO interventions and testing protocol.…”

Gait Changes in a Hemiplegic Patient Using an Ankle-Foot Orthosis with an Oil Damper: A Case Report

“…In a case report, Nolan et al showed the positive effect of a dynamic AFO on a patient's overall gait, in particular improved hip joint movement during gait [6]. Also, a specially designed carbon fiber AFO that allows ankle joint movement was shown to produce significantly greater push-off in children with hemiplegia [7]. An AFO with an oil dampner (AFO-OD), which was developed to assist the heel rocker function, is another type of AFO that facilitates active ankle joint movement during gait [8].…”