Neuromusculoskeletal Mechanics Research Program, University of Alberta, Edmonton, AB, Canada.
Gait Posture. 2012 May;36(1):85-9. doi: 10.1016/j.gaitpost.2012.01.007. Epub 2012 Feb 14.
Joint angle is the relative rotation between two segments where one is a reference and assumed to be non-moving. However, rotation of the reference segment will influence the system's spatial orientation and joint angle. The purpose of this investigation was to determine the contribution of leg and calcaneal rotations to ankle rotation in a weight-bearing task. Forty-eight individuals performed partial squats recorded using a 3D motion capture system. Markers on the calcaneus and leg were used to model leg and calcaneal segment, and ankle joint rotations. Multiple linear regression was used to determine the contribution of leg and calcaneal segment rotations to ankle joint dorsiflexion. Regression models for left (R(2)=0.97) and right (R(2)=0.97) ankle dorsiflexion were significant. Sagittal plane leg rotation had a positive influence (left: β=1.411; right: β=1.418) while sagittal plane calcaneal rotation had a negative influence (left: β=-0.573; right: β=-0.650) on ankle dorsiflexion. Sagittal plane rotations of the leg and calcaneus were positively correlated (left: r=0.84, P<0.001; right: r=0.80, P<0.001). During a partial squat, the calcaneus rotates forward. Simultaneous forward calcaneal rotation with ankle dorsiflexion reduces total ankle dorsiflexion angle. Rear foot posture is reoriented during a partial squat, allowing greater leg rotation in the sagittal plane. Segment rotations may provide greater insight into movement mechanics that cannot be explained via joint rotations alone.
关节角度是两个节段之间的相对旋转，其中一个节段是参考，被认为是不运动的。然而，参考节段的旋转会影响系统的空间方位和关节角度。本研究的目的是确定在负重任务中腿和跟骨旋转对踝关节旋转的贡献。48 名个体进行了部分深蹲，记录使用三维运动捕捉系统。在跟骨和腿上标记的标记用于对腿和跟骨节段以及踝关节旋转进行建模。多元线性回归用于确定腿和跟骨节段旋转对踝关节背屈的贡献。左（R(2)=0.97）和右（R(2)=0.97）踝关节背屈的回归模型具有统计学意义。矢状面腿旋转有积极的影响（左：β=1.411；右：β=1.418），而矢状面跟骨旋转有负面影响（左：β=-0.573；右：β=-0.650）对踝关节背屈。矢状面腿和跟骨的旋转呈正相关（左：r=0.84，P<0.001；右：r=0.80，P<0.001）。在部分深蹲时，跟骨向前旋转。跟骨与踝关节背屈同时向前旋转会减少总踝关节背屈角度。在部分深蹲期间，后脚姿势重新定向，允许在矢状面中进行更大的腿部旋转。节段旋转可能提供对运动力学的更深入了解，这些运动力学不能仅通过关节旋转来解释。
