Effect of shoulder tightness on glenohumeral translation, scapular kinematics, and scapulohumeral rhythm in subjects with stiff shoulders

• Published in: Journal of orthopaedic research 2006-05, Vol.24 (5), p.1044-1051
• Main Authors: Lin, Jiu-jenq, Lim, Hyun K., Yang, Jing-Lan
• Format: Article
• Language: English
• Subjects: 3D electromagnetic motion analysis; Adult; Aged; Biomechanical Phenomena; Humans; Humerus - physiopathology; Joint Instability; Middle Aged; Range of Motion, Articular; Scapula - physiopathology; shoulder; Shoulder Impingement Syndrome - physiopathology; Shoulder Joint - physiopathology; Shoulder Pain - physiopathology; tightness; translation
• ISSN: 0736-0266; 1554-527X
• DOI: 10.1002/jor.20126

Shoulder tightness may cause altered kinematics and lead to development of subacromial impingement, tendinitis, and degenerative changes. In this investigation, the humeral head translations, scapular kinematics, and scapulohumeral rhythm were determined with a three‐dimensional electromagnetic tracking device during arm elevations in six subjects with anterior shoulder tightness and in six subjects with posterior shoulder tightness to study the effects of anterior/posterior tightness on shoulder kinematics. Subjects with anterior tightness showed lower slopes in curves of glenohumeral elevation plotted against scapular upward rotation (scapulohumeral rhythm, 0.11 to 0.32; p = 0.021) and less posterior scapular tilt (2.9 to 7.5°; p = 0.002) during arm elevations when compared to the group with posterior tightness. The humeral head was positioned less posteriorly (2.2 to 3.4 mm; p = 0.004) and more superiorly (3.8 to 7.0 mm; p