Doorenbosch C A, Mourits A J, Veeger D H, Harlaar J, van der Helm F C
Department of Rehabilitation Medicine, University Hospital Vrije Universiteit, Amsterdam, The Netherlands.
J Orthop Sports Phys Ther. 2001 Mar;31(3):133-7. doi: 10.2519/jospt.2001.31.3.133.
A cross-sectional, descriptive study of shoulder movements conducted on nonimpaired subjects.
To investigate whether a single functional rotation axis about the shoulder complex can be determined during elevation in the coronal or sagittal planes, and to identify their location.
Accurate measurement of isokinetic torques about a joint requires alignment of the dynamometer axis with an assumed rotation axis of the joint. To assess shoulder function on a dynamometer, the location of a single rotation axis is not evident because the shoulder joint motion is based on several anatomical joints. Therefore, the rotation axis where humerothoracic movements occur should be judged as a functional rotation axis.
During slow elevation movements in the sagittal and coronal plane, the position of the epicondyle and acromion were recorded with a motion analysis system. The motion trajectory of the elbow coordinates was fitted to a circle and considered an estimate of the functional shoulder joint rotation axis in the specified plane.
The fitted trajectory appeared to be very accurate (root-mean-square error < 2%; N = 7). In the sagittal plane, the estimated functional rotation axis was found at the humeral head; in the coronal plane, it was located about 13 centimeters medial relative to the acromion.
The shoulder complex of nonimpaired subjects can act as a hinge joint of the upper arm relative to the thorax during elevation in each measured plane.
对未受损受试者进行的肩部运动横断面描述性研究。
探讨在冠状面或矢状面抬高过程中是否能确定围绕肩部复合体的单一功能旋转轴，并确定其位置。
准确测量关节等速扭矩需要将测力计轴与关节的假定旋转轴对齐。为了在测力计上评估肩部功能，单一旋转轴的位置并不明显，因为肩关节运动基于多个解剖关节。因此，肱骨胸廓运动发生的旋转轴应被判定为功能旋转轴。
在矢状面和冠状面的缓慢抬高运动过程中，使用运动分析系统记录肱骨髁和肩峰的位置。将肘部坐标的运动轨迹拟合为一个圆，并将其视为特定平面内功能性肩关节旋转轴的估计值。
拟合轨迹看起来非常准确（均方根误差<2%；N = 7）。在矢状面，估计的功能旋转轴位于肱骨头处；在冠状面，它位于相对于肩峰内侧约13厘米处。
在每个测量平面抬高过程中，未受损受试者的肩部复合体可作为上臂相对于胸廓的铰链关节。
