Clavicular motion

The scapulohumeral rhythm is a free-flowing and synchronous movement of the scapula and humerus. During abduction, the scapula rotates as the humerus elevates. For every 15 degrees of abduction, humeral elevation accounts for 10 degrees and scapular rotation accounts for 5 degrees. Dysfunction of humeral elevation or of scapular rotation can disturb this rhythm and interfere with shoulder function. Dysfunction of clavicular motion can also interfere with this rhythm. 

The clavicle moves during most shoulder activity. Dysfunctions in clavicular motion can interfere with normal shoulder movement. The combined axial rotation of the sternoclavicular joint (30 degrees) and the acromioclavicular joint (30 degrees) allows the normal 60 degrees of rotation of the scapula on full abduction of the shoulder. 

The osteopathic structural examination was remarkable for severe exhalation restrictions of ribs three to ten with rigid intercostal muscles bilaterally. In addition, there was markedly decreased diaphragmatic, thoracic inlet/outlet, sternal, and clavicular motion. Somatic dysfunctions included OAESrRi, C2ESrRr, and T2-T6NSiRr with increased tonicity of the intrascapular paravertebral muscles. 

Total flexion of the shoulder joint can also be divided into three phases. In the first phase (0 to 60 degrees), the muscles used are the anterior fibers of the deltoid, the coracobrachialis, and the clavicular fibers of the pectoralis major. Motion is limited by the tension of the coracohu-meral ligament and by the resistance offered by the teres minor, teres major, and infraspinatus muscles. 

How the first rib, at its sternal attachment, is directly influenced by clavicular and sternal motion... 

In abduction, the distal end of the clavicle moves superiorly and the proximal end moves inferi-orly. The physician tests motion in abduction by placing her index finger on the clavicular head next to the sternum while the patient is supine, the physician then asks the patient to shrug (Fig. 80-2]. A caudad movement should be palpated with normal motion at the sternoclavicular joint... 

Fracture of the shoulder is most commonly seen at the surgical neck of the humerus in adults. Children are more likely to present with clavicular fractures. Falls onto the outstretched arm are probably the most common cause of fractures in the shoulder girdle. Motion must be restored to the shoulder girdle as quickly as is possible after healing of the fracture to assure a return of normal mobility. 

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