Karduna A R, Williams G R, Williams J L, Iannotti J P
Department of Bioengineering and Orthopaedic Surgery, University of Pennsylvania, Philadelphia 19104, USA.
J Orthop Res. 1996 Nov;14(6):986-93. doi: 10.1002/jor.1100140620.
Despite recent interest in the study of shoulder kinematics, there is considerable controversy in the literature regarding translations at the glenohumeral joint. The purpose of this study was to investigate the key factors that control shoulder motions, thus leading to a better understanding of joint function. Translation and rotation patterns were studied in fresh-frozen glenohumeral joints of human cadavers with a six-degrees-of-freedom magnetic tracking device. Shoulders were positioned from maximal internal to external rotation at several arm positions (various elevations and planes of motion). In order to determine the effect of muscle forces, joints were positioned both actively and passively. Additionally, articular surface geometry and ligament origin-insertion wrap lengths were measured to assess their influences on joint kinematics. When joints were positioned passively, large translations were observed at the extremes of motion. With active positioning, muscle forces tended to limit humeral head translations, principally by restricting rotational ranges of motion. However, when data from the passive model were reanalyzed by considering only the rotational ranges of motion seen actively, no significant differences in translation were found between the two models. Joint conformity was found to have a significant influence on translations during active positioning but not during passive positioning. Glenohumeral ligament wrap lengths, however, correlated with translations when joints were positioned passively but not when positioned actively. Findings from this study emphasize the importance of muscle forces in keeping the humeral head centered in the glenoid. Although large translations are possible, they can be achieved only with increases in rotational ranges of motion associated with the removal of muscle force. Additionally, joint conformity appears to play a role in controlling translations during active motions, whereas capsular constraints become more important during passive motions.
尽管近期对肩部运动学的研究颇受关注，但文献中关于盂肱关节平移仍存在相当大的争议。本研究的目的是探究控制肩部运动的关键因素，从而更好地理解关节功能。使用六自由度磁跟踪装置，对人类尸体的新鲜冷冻盂肱关节的平移和旋转模式进行了研究。在几个手臂位置（不同的抬高角度和运动平面），将肩部从最大内旋位置调整到外旋位置。为了确定肌肉力量的影响，分别在主动和被动状态下对关节进行定位。此外，测量了关节面几何形状和韧带起止点的包裹长度，以评估它们对关节运动学的影响。当关节处于被动位置时，在运动极限处观察到较大的平移。在主动定位时，肌肉力量倾向于限制肱骨头的平移，主要是通过限制运动的旋转范围。然而，当仅考虑主动状态下的旋转范围对被动模型的数据重新分析时，两个模型之间在平移方面未发现显著差异。发现在主动定位过程中关节匹配度对平移有显著影响，而在被动定位过程中则没有。然而，盂肱韧带的包裹长度在关节被动定位时与平移相关，而在主动定位时则不然。本研究结果强调了肌肉力量在保持肱骨头位于关节盂中心的重要性。尽管可能出现较大的平移，但只有在去除肌肉力量并增加旋转运动范围的情况下才能实现。此外，关节匹配度似乎在主动运动过程中对控制平移起作用，而在被动运动过程中关节囊的限制变得更加重要。
