Kuechle D K, Newman S R, Itoi E, Morrey B F, An K N
Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA.
J Shoulder Elbow Surg. 1997 Sep-Oct;6(5):429-39. doi: 10.1016/s1058-2746(97)70049-1.
The instantaneous muscle moment arms of 10 shoulder muscles including the three portions of the deltoid and the rotator cuff and scapulohumeral muscle groups during four specified glenohumeral motions were calculated. Moment arm values were derived from a plot of tendon excursion versus glenohumeral joint rotation angle during horizontal flexion along the 90 degrees elevation plane and elevation in the sagittal, scapular, and coronal planes. The deltoid had the largest moment arm in elevation. The anterior deltoid has a larger moment arm in the anterior planes, whereas the midportion is greater in the scapular and coronal planes. The muscles with the largest depressor (adductor) moment arms are the pectoralis major, latissimus dorsi, and teres major. Contrary to the findings of other investigators, the supraspinatus and infraspinatus have a smaller potential elevation torque in the scapular plane than has been previously reported. Furthermore the subscapularis may potentially be a more important elevator in the scapular plane than either the supraspinatus or infraspinatus, especially in the latter phases of motion. The pectoralis major has the largest horizontal flexion moment arm with the humerus elevated 90 degrees, whereas the posterior deltoid and infraspinatus have the largest horizontal extension moment arms in this plane.
计算了包括三角肌三个部分、肩袖肌群和肩胛肱骨肌群在内的10块肩部肌肉在四种特定盂肱关节运动过程中的瞬时肌肉力臂。力臂值来自于在沿90度抬高平面的水平屈曲以及矢状面、肩胛面和冠状面抬高过程中肌腱偏移与盂肱关节旋转角度的关系图。三角肌在抬高时力臂最大。三角肌前部在前面的平面中力臂较大，而中部在肩胛面和冠状面中力臂更大。具有最大下压（内收）力臂的肌肉是胸大肌、背阔肌和大圆肌。与其他研究者的发现相反，冈上肌和冈下肌在肩胛面中的潜在抬高扭矩比之前报道的要小。此外，肩胛下肌在肩胛面中可能是比冈上肌或冈下肌更重要的上抬肌，尤其是在运动的后期阶段。当肱骨抬高90度时，胸大肌具有最大的水平屈肌力臂，而在该平面中，三角肌后部和冈下肌具有最大的水平伸肌力臂。
