Wuelker N, Korell M, Thren K
Orthopaedic Department, Hannover Medical School, Germany.
J Shoulder Elbow Surg. 1998 Jan-Feb;7(1):43-52. doi: 10.1016/s1058-2746(98)90182-3.
Stability of the glenohumeral joint with an anterior, posterior, and inferior displacement force of 50 N was measured in a dynamic shoulder model. Controlled hydrodynamic actuator forces were applied to the deltoid muscle and to the rotator cuff in seven anatomic specimens. During elevation of the arm the position of the humerus was measured with a six-degree-of-freedom ultrasonic sensor device. The rotational center of the humeral head was used as a reference point for translation. A displacement force of 50 N led to significant humeral head displacement anteriorly and posteriorly but not inferiorly. A 50% reduction of rotator cuff forces increased anterior displacement by 46% and posterior displacement by 31%. Venting of the glenohumeral joint space and of the subacromial bursa resulted in a 50% increase of anterior displacement, a 19% increase of posterior displacement, and significant inferior displacement. This study demonstrates that in addition to passive stabilizers and negative intraarticular pressure, rotator cuff force significantly contributes to stabilization of the glenohumeral joint during arm motion. Muscle strength and coordination should gain more emphasis in the diagnosis and treatment of shoulder instability.
在一个动态肩部模型中，测量了肱盂关节在50牛的前向、后向和下向位移力作用下的稳定性。对7个解剖标本的三角肌和肩袖施加可控的流体动力致动器力。在手臂抬高过程中，用一个六自由度超声传感器装置测量肱骨的位置。肱骨头的旋转中心用作平移的参考点。50牛的位移力导致肱骨头显著向前和向后移位，但没有向下移位。肩袖力量减少50%会使前向移位增加46%，后向移位增加31%。肱盂关节间隙和肩峰下囊的排气导致前向移位增加50%，后向移位增加19%，以及显著的向下移位。这项研究表明，除了被动稳定器和关节内负压外，肩袖力量在手臂运动过程中对肱盂关节的稳定有显著贡献。在肩部不稳定的诊断和治疗中，肌肉力量和协调性应得到更多重视。
