Shoulder Joint

 The spherical head of the humerus with the small, shallow, somewhat pear-shaped glenoid fossa of the scapula (Ball and Socket Joint)  Both bones are covered with a hyaline cartilage  The humerus head is thicker in the center and the lining of the cavity is thicker on the outside (makes for a nice fit)  The glenoid labrum helps to deepen the joint and hold the head of the humerus in place.

1. Coracohumeral ligament 2. Glenohumeral ligament (3 bands) 3. Coracoacromial ligament

 Flexion  Hyperflexion  Extension  Hyperextension  Abduction  Adduction  Outward (Lateral) rotation  Inward (medial) rotation  Circumduction

1. The slope of the glenoid fossa 2. The tightening of the upper part of the capsule and of the coracohumeral ligament 3. The activity of the supraspinatus muscle and to a lesser extent the posterior fibers of the deltoid

 Rotator Cuff (musculotendinous cuff) 1. Supraspinatus – Abduction of arm – stability 2. Infraspinatus 3. Teres minor – seem to act as one – hold the head of the humerus in the glenoid fossa 4. Subscapularis – Anterior scapula to the head of the humerus

 Other muscles 1. Pectoralis major – clavicular and sternal – important for pushing, throwing, and punching 2. Coracobrachialis – forward movements of the humerus 3. Biceps brachii 4. Tricpes brachii 5. Deltoid 6. Latisimus dorsi 7. Teres major

 Acromioclavicular sprain  Fracture of the clavicle  Dislocation of the shoulder (luxation)  Rotator cuff strains or tears (rupture)