Influence of Ankle Motion on Bilateral Amputee Gait

本研究旨在探讨踝关节假体运动对双侧肢体截肢者步态力学的影响。双侧双腿截肢者走路时经常双腿僵硬或僵硬，部分原因可能是假肢踝关节的顺应性和活动范围不足。他们可能试图通过在步态过程中增加能量消耗的代偿行动来克服假肢缺陷。大多数关于截肢者步态的文献都是关于单侧截肢者的，但根据单侧截肢者的数据很难确定哪些方面需要显著改善。与单侧截肢者相比，双腿截肢者由于行走时能量需求增加，行走速度较慢，假体部件更需要改进。双侧截肢者在步态过程中的假体性能更容易评估，因为他们在行走时有更少的生理控制选择。有关双腿截肢者康复的文献报道很少，也没有发表关于双腿截肢者的定量步态研究。我们将在弗吉尼亚州芝加哥运动分析研究实验室对30名双侧经胫骨(膝下)和经股(膝上)截肢者进行步态定量分析，这些截肢者使用和不使用可增加脚踝运动的假体部件。这些部件包括用于增加踝关节背屈/趾屈和内翻/外翻的Endolite Multiflex踝关节，以及用于增加横向平面旋转的Otto Bock踝关节扭转适配器。我们假设，增加踝关节运动将显著改善双侧下肢截肢者的步态。我们还将研究15名身体健全的人的模拟双侧截肢步态，为他们安装尽可能减少膝盖和脚踝运动的矫形器。我们假设，踝关节和膝盖受限的健全人行走时，其步态特征与双侧截肢者相似。健全人的步行模式为不同类型的病理性步态的比较提供了有用的基础，我们相信改变健全人的运动系统可以提供有关病理性步态机制的有价值的信息。这项研究的结果将有助于识别当前假肢技术中限制截肢者正常行走模式的局限性。

We propose to investigate the effect of prosthetic ankle motion on the mechanics of bilateral lower-limb amputee gait. Bilateral lower-limb amputees often walk with rigid or stiff legs, which may be due in part to insufficient compliance and ranges of motion in their prosthetic ankles. They may attempt to overcome prosthetic deficiencies with compensatory actions that increase their energy expenditure during gait. Most of the literature pertaining to amputee gait is concerned with persons having unilateral amputations, but it is difficult to identify areas where significant improvement is needed based upon data from unilateral amputee gait. Compared with unilateral amputees, persons with bilateral leg amputations have a greater need for improvement in prosthetic componentry because of their increased energy demand as they walk and their low speed of walking. Prosthetic performance during gait is easier to evaluate in bilateral amputees because they have fewer physiological control options available to them while they ambulate. Few outcome studies have been reported in the literature regarding their rehabilitation, and there have been no published quantitative gait studies on bilateral leg amputees to date. We will perform quantitative gait analyses in the VA Chicago Motion Analysis Research Laboratory on 30 bilateral transtibial (below-knee) and transfemoral (above-knee) amputees walking with and without prosthetic components that increase ankle motion. These components include the Endolite Multiflex Ankle to increase ankle dorsiflexion/plantarflexion and inversion/eversion, and the Otto Bock Ankle Torsion Adapter to increase transverse plane rotation. We hypothesize that increased ankle motion will significantly improve the gaits of bilateral lower-limb amputees. We will also study simulated bilateral amputee gait in 15 able- bodied persons by fitting them with orthoses that minimize knee and ankle motion. We hypothesize that able-bodied persons walking with constrained ankles and knees will have gait characteristics similar to bilateral amputees. The able-bodied walking pattern serves as a useful basis of comparison for different types of pathological gait, and we believe that altering the locomotor system of the able-bodied person can yield valuable information concerning the mechanisms of pathological gait. The results from this study will aid in identifying limitations in current prosthetic technology that inhibit normal patterns of walking in amputees.