Jenkyn Thomas R, Anas Kiersten, Nichol Alexander
Wolf Orthopaedic Biomechanics Laboratory, Department of Mechanical and Materials Engineering, Faculty of Engineering, The University of Western Ontario, London ON N6A 5B9, Canada.
J Biomech Eng. 2009 Mar;131(3):034504. doi: 10.1115/1.2907750.
Gait analysis using optical tracking equipment has been demonstrated to be a clinically useful tool for measuring three-dimensional kinematics and kinetics of the human body. However, in current practice, the foot is treated as a single rigid segment that articulates with the lower leg, meaning the motions of the joints of the foot cannot be measured. A multisegment kinematic model of the foot was developed for use in a gait analysis laboratory. The foot was divided into hindfoot, talus, midfoot, and medial and lateral forefoot segments. Six functional joints were defined: Ankle and subtalar joints, frontal and transverse plane motions of the hindfoot relative to midfoot, supination-pronation twist of the forefoot relative to midfoot, and medial longitudinal arch height-to-length ratio. Twelve asymptomatic subjects were tested during barefoot walking with a six-camera optical stereometric system and passive markers organized in triads. Repeatability of reported motions was tested using coefficients of multiple correlation. Ankle and subtalar joint motions and twisting of the forefoot were most repeatable. Hindfoot motions were least repeatable both within subjects and between subjects. Hindfoot and forefoot pronations in the frontal place were found to coincide with dropping of the medial longitudinal arch between early to midstance, followed by supination and rising of the arch in late stance and swing phase. This multisegment foot model overcomes a major shortcoming in current gait analysis practice-the inability to measure motion within the foot. Such measurements are crucial if gait analysis is to remain relevant in orthopaedic and rehabilitative treatment of the foot and ankle.
使用光学跟踪设备进行步态分析已被证明是一种临床上用于测量人体三维运动学和动力学的有用工具。然而，在当前的实践中，足部被视为与小腿相连的单个刚性节段，这意味着足部关节的运动无法测量。为步态分析实验室开发了一种多节段足部运动学模型。足部被分为后足、距骨、中足以及内侧和外侧前足节段。定义了六个功能关节：踝关节和距下关节、后足相对于中足在额状面和横断面上的运动、前足相对于中足的旋前-旋后扭转以及内侧纵弓高度与长度之比。使用六台摄像机的光学立体测量系统和以三联体形式组织的被动标记，对12名无症状受试者进行了赤足行走测试。使用多重相关系数测试报告运动的可重复性。踝关节和距下关节运动以及前足扭转的可重复性最高。后足运动在受试者内部和受试者之间的可重复性最低。发现在额状面中后足和前足的旋前与早期至中期支撑期内侧纵弓下降同时发生，随后在支撑后期和摆动期出现旋后和足弓上升。这种多节段足部模型克服了当前步态分析实践中的一个主要缺点——无法测量足部内部的运动。如果步态分析要在足踝的骨科和康复治疗中保持相关性，这样的测量至关重要。
