Rancho Los Amigos Medical Center, 7601 East Imperial Highway, Bldg. 304, Downey, CA 90242, USA.
NeuroRehabilitation. 1997;8(2):119-38. doi: 10.3233/NRE-1997-8206.
Muscle weakness resulting from the combined effects of acute and late motor neuron pathology is the basic cause of post-polio dysfunction. Through their normal sensation and moter control, post-polio patients minimize their disability by useful substitutions. Orthoses are needed only when these substitutions either are inadequate or result in muscle or joint overuse. The areas most commonly showing late disability are the lower extremities, shoulders and low-back. In the lower extremities, the major muscle groups are the hip extensors and abductors, the knee extensors (quadriceps), ankle plantar flexors and dorsi flexors. Each group has a specific function which relates to one of the basic tasks of walking, weight acceptance, single limb support and swing. To determine orthotic needs, polio gait deviations representing useful substitutions must be differentiated from symptomatic dysfunction. Weight acceptance utilizes the quadriceps, hip extensors and hip abductors to establish a stable limb and provide shock absorbing mechanics. Substitutions to preserve weight bearing stability include sacrifice of normal shock absorbing knee flexion for quadriceps weakness, backward or lateral trunk lean for hip extensor and abductor weakness. Knee pain, excessive hyperextension and flexion contractures are indications for orthotic assistance with a KAFO. Orthotic designs relate to the type of knee joint (off-set, free, locked) and completeness of the AFO component. Low-back pain from hip substitutions or over use of the hip muscles requires a walking aid. Single limb support is the period when the limb and body advance over the supporting foot. The key muscle group is the soleus-gastrocnemius complex. Swing involves lifting and advancing the unloaded limb. While all three joints flex simultaneously, the hip flexors and ankle dorsi flexors are the critical muscles. A drop foot from ankle dorsiflexor weakness is the common disability. Excessive hip flexion is the usual substitution. An orthosis which assists dorsiflexion without obstructing loading response plantar flexion is the most functional design.
由于急性和晚期运动神经元病理的综合影响导致的肌肉无力，是发生肌病后功能障碍的基本原因。通过正常的感觉和运动控制，肌病后患者通过有用的代偿来尽量减少残疾。只有当这些代偿不足或导致肌肉或关节过度使用时，才需要矫形器。最常见的晚期残疾部位是下肢、肩部和下背部。在下肢，主要的肌肉群是髋关节伸肌和外展肌、膝关节伸肌（股四头肌）、踝关节跖屈肌和背屈肌。每个肌群都有一个特定的功能，与步行的基本任务之一有关，如承重、单肢支撑和摆动。为了确定矫形器的需求，必须区分代表有用代偿的肌病步态偏差与症状性功能障碍。承重利用股四头肌、髋关节伸肌和髋关节外展肌来稳定肢体并提供减震力学。为了保持承重稳定性而进行的代偿包括牺牲股四头肌无力时正常的减震膝关节屈曲、髋关节伸肌和外展肌无力时躯干向后或向侧倾斜。膝关节疼痛、过度伸展和屈曲挛缩是需要使用 KAFO 进行矫形辅助的指征。矫形设计与膝关节类型（偏置、自由、锁定）和 AFO 组件的完整性有关。由于髋关节代偿或过度使用髋关节肌肉引起的下背部疼痛需要使用助行器。单肢支撑是肢体和身体越过支撑脚向前推进的阶段。关键的肌肉群是比目鱼肌-跟腱复合体。摆动涉及抬起和向前推进未负重的肢体。虽然三个关节同时屈曲，但髋关节屈肌和踝关节背屈肌是关键肌肉。由于踝关节背屈肌无力导致的垂足是常见的残疾。过度的髋关节屈曲是常见的代偿。一种能够协助背屈而不妨碍负重反应跖屈的矫形器是最具功能性的设计。
