Szczerbik Ewa, Kalinowska Małgorzata
Department of Paediatric Rehabilitation, The Children's Memorial Health Institute, Warszawa, Poland.
Acta Bioeng Biomech. 2011;13(3):43-6.
Vicon motion system is an accurate equipment for objective gait analysis. According to clinical experience the most important source of errors in kinematics is marker misplacement. It seems that knee marker placement is especially important because of its direct influence on two body segments: thigh and shank. There is little data in the literature on how the misplacement of knee marker determines the changes of kinematic parameters. Therefore the aim of this study was to collect the kinematic data of subjects with different knee pathologies (one with knee flexion contracture, the second with knee hyperextension) while knee marker position was changed in a systematical way. They were walking with their natural, preferred speed. The data were collected using VICON460 motion system, the Helen Hayes marker set and Plug-In-Gait model. Then they were processed based on Polygon software. The results of both subjects showed the changes of kinematics, depending on the knee marker misplacement. The assessed joint ranges of angle change were: in knee, 18° in sagittal plane and 20° in frontal plane; in hip, 10° in sagittal plane and 24° in transversal plane; in ankle, 10° in sagittal plane and 25° in transversal plane. This paper presents the detailed data which could help the users of such systems to interpret the kinematic data.
Vicon运动系统是一种用于客观步态分析的精确设备。根据临床经验，运动学中最重要的误差来源是标记点放置错误。由于其对大腿和小腿这两个身体节段有直接影响，膝关节标记点的放置似乎尤为重要。关于膝关节标记点放置错误如何决定运动学参数变化的文献资料很少。因此，本研究的目的是在系统改变膝关节标记点位置的同时，收集患有不同膝关节病变（一名患有膝关节屈曲挛缩，另一名患有膝关节过伸）的受试者的运动学数据。他们以自然、偏好的速度行走。使用VICON460运动系统、海伦·海耶斯标记点集和插入式步态模型收集数据。然后基于Polygon软件对数据进行处理。两名受试者的结果均显示，运动学变化取决于膝关节标记点的放置错误。评估的关节角度变化范围为：膝关节矢状面18°，额状面20°；髋关节矢状面10°，横断面24°；踝关节矢状面10°，横断面25°。本文提供了详细数据，可帮助此类系统的用户解读运动学数据。
