School of Physiotherapy, La Trobe University, Melbourne, Victoria 3086, Australia.
Gait Posture. 2010 Apr;31(4):415-9. doi: 10.1016/j.gaitpost.2010.01.004. Epub 2010 Feb 21.
Motion analysis of participants with different body shapes under diverse conditions can be problematic when vital markers are occluded. The markers located over the anterior superior iliac spines are commonly occluded in older patients and during analysis of activities with trunk and hip flexion which can prevent accurate calculation of lower limb joint kinematics. Options to modify standard body models exist but have not been described in detail, and the effects on the lower limb kinematics are not known.
Three-dimensional motion analysis data were collected from 10 participants during level walking. A single trial from each participant was processed using the standard PlugIn Gait model and with four alternative modelling procedures where either one or both anterior pelvis markers were not labelled for all or part of the trial. Similarity of these alternative procedures to PlugIn Gait was assessed by comparison of peak kinematic characteristics and Root Mean Square (RMS) across the gait cycle.
The peak lower limb kinematics of all four alternative modelling procedures were similar to PlugIn Gait to within 4.57 degrees . The alternative procedure most similar to PlugIn Gait was less than 1.24 degrees different. The largest RMS was 2.88 degrees and the smallest was 0.92 degrees .
This study has presented several options for researchers and clinicians to modify the standard body models of motion analysis so that lower limb kinematics may be calculated without reliance on continuous visualisation of anterior pelvic markers. Although the alternative modelling processes are subject to different sources of error which need to be considered, the error is minimal.
在重要标记物被遮挡的情况下，对于不同体型的参与者在不同条件下的运动分析可能会出现问题。位于前上髂棘的标记物通常会被老年患者和进行躯干及髋关节弯曲活动分析时遮挡，这可能会妨碍下肢关节运动学的精确计算。存在修改标准人体模型的选项，但这些选项尚未详细描述，并且其对下肢运动学的影响也不清楚。
在水平行走过程中，从 10 名参与者中收集了三维运动分析数据。对每位参与者的单个试验分别使用标准 PlugIn Gait 模型和四种替代建模程序进行处理，在这些替代建模程序中，要么全部要么部分试验中都没有标记前骨盆标记物。通过比较步态周期中的峰值运动学特征和均方根（RMS）来评估这些替代程序与 PlugIn Gait 的相似性。
所有四种替代建模程序的下肢运动学峰值均与 PlugIn Gait 相似，差异在 4.57 度以内。与 PlugIn Gait 最相似的替代程序差异小于 1.24 度。最大 RMS 为 2.88 度，最小 RMS 为 0.92 度。
本研究为研究人员和临床医生提供了几种修改运动分析标准人体模型的选择方案，以便在不依赖于前骨盆标记物连续可视化的情况下计算下肢运动学。尽管替代建模过程会受到不同来源的误差的影响，需要加以考虑，但误差很小。
