Department of Orthopedic Surgery, School of Medicine, Keio University, Tokyo 160-8582, Japan.
J Shoulder Elbow Surg. 2013 Mar;22(3):333-9. doi: 10.1016/j.jse.2012.02.006. Epub 2012 May 18.
The clavicle serves as a strut between the thorax and scapula, and lack of this function could affect shoulder mobility. We hypothesized that clavicular discontinuity changes shoulder kinematics, particularly affecting scapular motion.
The study used 14 cadaveric shoulders. Cadavers were stabilized in the sitting position. Manual elevation in the sagittal, scapular, and coronal planes was performed in the intact and clavicular discontinuity models. The thorax-scapula distance and 3-dimensional scapular motion during shoulder elevation were recorded using an electromagnetic tracking device. The differences between the 2 experimental models at each position were analyzed.
Clavicular discontinuity resulted in a decreased thorax-scapula distance and in reduced external rotation, upward rotation, and posterior tilting of the scapula. The kinematic changes were observed during elevations in all 3 planes but were greatest in the sagittal plane compared with the scapular and coronal planes.
The findings of this study revealed that discontinuity of the clavicle affects shoulder kinematics. Because of its anatomic shape and position, the clavicle stabilizes the external, upward, and posterior rotation of the scapula during arm movement. This function of the clavicle may assist glenohumeral joint motion and help prevent subacromial impingement.
Basic Science Study, Biomechanics, Cadaver Model.
锁骨作为连接胸廓和肩胛骨的支柱，如果缺少这个功能，可能会影响肩部的活动度。我们假设锁骨连续性中断会改变肩部运动学，特别是影响肩胛骨运动。
本研究使用了 14 具尸体肩膀。将尸体稳定在坐姿。在完整和锁骨连续性中断模型中，分别在矢状面、肩胛骨和冠状面手动提升肩膀。使用电磁跟踪装置记录在肩膀提升过程中胸锁距离和三维肩胛骨运动。分析了两种实验模型在每个位置的差异。
锁骨连续性中断导致胸锁距离减小，肩胛骨外旋、上旋和后倾减少。在所有三个平面的提升过程中都观察到了运动学变化，但与肩胛骨和冠状面相比，在矢状面最为明显。
本研究结果表明，锁骨连续性中断会影响肩部运动学。由于其解剖形状和位置，锁骨在手臂运动过程中稳定了肩胛骨的外旋、上旋和后倾。锁骨的这个功能可能有助于盂肱关节运动，并有助于防止肩峰下撞击。
基础科学研究，生物力学，尸体模型。
