痉挛型脑瘫儿童佩戴不同类型踝足矫形器后下肢生物力学的变化

目的：比较痉挛型脑瘫患儿在佩戴传统硬直式踝足矫形器（RAFO）与新型动力型踝足矫形器（DAFO）后所产生的下肢生物力学变化及差异,为临床选用更合适的踝足矫形器（AFO）进行治疗提供理论依据。方法：采用Vicon三维步态分析系统及Kislter测力台分别测评16例痉挛型脑瘫患儿在裸足、佩戴RAFO及DAFO 3种条件下的下肢关节运动学,动力学以及时间空间参数。结果：与裸足比较,佩戴RAFO后步长增加0.05 m,DAFO增加0.07 m;首次着地RAFO增加9°,DAFO增加11.3°;支撑相中RAFO增加10°,DAFO增加11°,且2种方法踝关节背屈角度均明显增大,跖屈角度明显减小;跖屈力矩RAFO增加0.33 Nm/kg,DAFO增加0.37 Nm/kg（均P〈0.05）。DAFO的踝关节活动范围较RAFO增加7°（P〈0.05）。结论：2种不同的踝足矫形器均能够有效提高痉挛型脑瘫患儿的步行能力及行走过程中的踝关节背伸功能。DAFO在矫正踝关节活动及马蹄足畸形方面效果好于RAFO,并可减轻RAFO所导致的踝关节功能受限。

Biomechanics Changes at Lower Limb Joints between Different Types of Ankle Foot Orthosis in Children with Cerebral Palsy

Objective： To understand the kinematics and kinetics variables at lower limb joints between rigid ankle foot orthosis（RAFO） and dynamic ankle foot orthosis（DAFO） in children with spastic cerebral palsy（CP） in order to find a better design for the ankle foot orthosis（AFO） in future.Methods： Sixteen spastic cerebral palsy children（10 boys,6 girls,aged from 4 to 8 years,average age=6.25±1.18 years） were recruited from the Rehabilitation Department of Shanghai 6th People＇s Hospital（China）.Kinematics parameters were measured by using Vicon three-dimensional gait analysis system and the kinetics changes were examined by two Kislter force platforms at the same time under three conditions：（1） RAFO,（2） DAFO and（3） Bare foot only.Results： Both RAFO and DAFO showed significantly larger stride length than the bare foot only（RAFO increased 0.05 m and DAFO increased 0.07 m,P0.05）,and significantly higher dorsiflexion degrees were found in initial contact（RAFO increased 9° and DAFO increased 11.3°,P0.05） and stance phase（RAFO increased 10° and DAFO increased 11°,P0.05） under both two AFO conditions at same time.RAFO showed significantly smaller range of motion at ankle joint during walking that the dynamic ankle foot orthosis and bare foot only（7° decreased when compared to the DAFO and 8° decreased when compared to the bare foot condition,P0.05）.Besides,DAFO showed significantly higher ankle plantarflexion degrees when compared to the RAFO（5.5° increased,P0.05）.Both two AFO conditions showed an obviously higher ankle plantar moment than bare foot condition（0.33 Nm/kg increased in RAFO and 0.37 Nm/kg increased in DAFO,P0.05）,and no other kinetic or kinematic differences were found in hip and knee joint under three conditions.Conclusion： Both two different AFO can help to improve the walking ability of CP children and offer a better foot position during walking.The DAFO showed a bigger range of motion and better position at ankle joint,and the higher plantarflexion degrees.