Petit Daniel J, Willson John D, Barrios Joaquin A
School of Engineering, University of Dayton, Dayton, OH.
J Appl Biomech. 2014 Feb;30(1):173-8. doi: 10.1123/jab.2012-0147.
Efforts to compare different surface marker configurations in 3-dimensional motion analysis are warranted as more complex and custom marker sets become more common. At the knee, different markers can been used to represent the proximal shank. Often, two anatomical markers are placed over the femoral condyles, with their midpoint defining both the distal thigh and proximal shank segment ends. However, two additional markers placed over the tibial plateaus have been used to define the proximal shank end. For this experiment, simultaneous data for both proximal shank configurations were independently collected at two separate laboratories by different investigators, with one laboratory capturing a walking population and the other a running population. Common discrete knee joint variables were then compared between marker sets in each population. Using the augmented marker set, peak knee flexion after weight acceptance was less (1.2-1.7°, P < .02) and peak knee adduction was greater (0.7-1.4°, P < .001) in both data sets. Similarly, the calculated peak knee flexion moment was less by 15-20% and internal rotation moment was greater by 11-18% (P < .001). These results suggest that the calculation of knee joint mechanics are influenced by the proximal shank's segment endpoint definition, independent of dynamic task, investigator, laboratory environment, and population in this study.
随着更复杂和定制化的标记集变得越来越普遍，在三维运动分析中比较不同表面标记配置的努力是有必要的。在膝盖处，可以使用不同的标记来表示小腿近端。通常，两个解剖学标记放置在股骨髁上，它们的中点定义了大腿远端和小腿近端节段的末端。然而，也有人使用另外两个放置在胫骨平台上的标记来定义小腿近端的末端。在本实验中，由不同的研究人员在两个独立的实验室分别独立收集了两种小腿近端配置的同步数据，一个实验室收集步行人群的数据，另一个收集跑步人群的数据。然后比较了每个群体中不同标记集之间常见的离散膝关节变量。使用增强标记集，在两个数据集中，负重后膝关节最大屈曲角度更小（1.2 - 1.7°，P < 0.02），膝关节最大内收角度更大（0.7 - 1.4°，P < 0.001）。同样，计算得出的膝关节最大屈曲力矩减少了15 - 20%，内旋力矩增加了11 - 18%（P < 0.001）。这些结果表明，在本研究中，膝关节力学的计算受小腿近端节段端点定义的影响，与动态任务、研究人员、实验室环境和人群无关。
