Sports Medicine Research Department, Sports Surgery Clinic, Dublin, Ireland; Department of Life Sciences, University of Roehampton, London, UK.
Sports Medicine Research Department, Sports Surgery Clinic, Dublin, Ireland; Queen's School of Engineering, University of Bristol, Bristol, UK.
J Biomech. 2020 Mar 5;101:109635. doi: 10.1016/j.jbiomech.2020.109635. Epub 2020 Jan 30.
The conventional gait model (CGM) refers to several closely related biomechanical models used in the objective analysis of human motion. Their use has become popular in the analysis of change of direction tasks to inform best practice in the prevention and rehabilitation of anterior cruciate ligament injury. As externally-placed markers define segment axes origins and orientations, kinematic and kinetic outputs from the CGM are sensitive to marker placement. The aim of this investigation was to quantify the sensitivity of lower extremity kinematics and knee moments to systematic differences in marker placement across the stance phase of a change of direction task. Systematic anterior/posterior displacements were applied to the lateral thigh, femoral epicondyle and tibia markers in software. One-dimensional statistical parametric mapping was used to determine the effect of marker placement across the entire stance phase of a 90° change of direction task. Marker placement error within previously reported inter-tester variability ranges caused significant differences in knee abduction moment, hip rotation angle, knee rotation angle, ankle abduction and rotation angle across various periods of stance. Discrete measures of these variables have been associated with increased frontal plane knee loading during change of direction, considered a key mechanism of anterior cruciate ligament injury. Systematic differences in marker placement may lead to incorrect group statistical inferences in such discrete measures.
传统步态模型 (CGM) 是指在人体运动的客观分析中使用的几种密切相关的生物力学模型。它们在变向任务分析中的应用越来越受欢迎，旨在为前交叉韧带损伤的预防和康复提供最佳实践建议。由于外部标记定义了节段轴的起点和方向，CGM 的运动学和动力学输出对标记放置敏感。本研究的目的是量化下肢运动学和膝关节力矩对变向任务支撑相阶段标记放置系统差异的敏感性。在软件中对大腿外侧、股骨髁和胫骨标记进行系统的前后位移。一维统计参数映射用于确定在 90°变向任务的整个支撑相阶段标记放置的影响。在先前报道的组内测试者变异性范围内的标记放置误差导致膝关节外展力矩、髋关节旋转角度、膝关节旋转角度、踝关节外展和旋转角度在支撑相的不同阶段出现显著差异。这些变量的离散测量值与变向过程中前平面膝关节加载增加有关，这被认为是前交叉韧带损伤的关键机制。标记放置的系统差异可能导致此类离散测量的组统计推断错误。
