Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== SHOULDER JOINT ====== * Shoulder joint * Type * Ball and socket , synovial * Articular surface * Glenoid cavity of scapula * Head of humerus * Features * Weak joint * Due to small and shallow to hold head of humerus in place * But permits great mobility * Stability factors * 1. Coraclacromial arch or secondayr socket for head of humrus * 2. Musculotendinous cuff * 3. Glenoidal labrum helps in deeping glenoid fossa * 4. Muscles attaching humerus to pectoral girdle * 5. Atmospheric presure * Ligaments * Capsular ligament * Very loose , * permits free movements , * least supported * Inferiorly , where dislocation common * May damage axillary nerve * Medially * Attached to scapula beyond supraglenoid tubercle and margins of labrum * Laterally * Attached to anatomical neck of humerus * Exception * Inferiorly attachment extends to surgical neck * Superiorly - deificient for passage of long head of tendon of biceps brachi * Anteriorly - capsule is reinforced by supplemental bands called * Glenohumeral ligaments. * Superior , middle and inferior * Area between superior and inferior glenohumeral ligament is a point of weakness in capsule ( foramen of weitbrecht ) * Anterior dislocation of humeral head * Capsule lined by synovial membrane * An extension of this forms a tubular sheath for tendon of long head of biceps brachii * Coracohumeral ligament * Extent. * From root of coracoid process to neck of humerus opposite greater tubercle * Gives strength to capsule * Transverse humeral ligament * Bridges upper part of bicipital groove of humerus * Between greater and lesser tubercle * Tendons passes deep to it * Glenoidal labrum * Fibrocartilaginous rim * covers margins of glenoid cavity * Bursae * Subacromial or deltoid bursa (A) * Subscaoularis bursa (B) * Infraspinatus bursa * A and B are commonly continuous with each other but may be separate * Relations * Superiorly - coraclacromial bursa , subacromial bursa , supraspinatus , deltoid * Inferiorly - long head of triceps , axillary nerves , posterior circumflex humeral artery * Anteriroyl - subscaoularis , coracobrahialis, deltoid, short head of biceps * Posteriorly - infraspinatus , teres minor , deltoid * Within joint - tendon of long head of biceps brachii * Blood supply - * Anterior circumflex humeral vessels * Posterior circumflex humeral vessels * Suorascapular vessels * Subscapular vessels * Nerve supply * Axillary nerve * Musculocutaneous nerve * Suorascapular nerve * Movements * Flexion * Extension * Parallel to glenoid cavity * Adduction * Abduction * Medial rotation * Lateral rottation * Circumduction ^ ^ ^ | Type | Synovial ball and socket joint; multiaxial | | Articular surfaces | Glenoid fossa of scapula, head of humerus; glenoid labrum | | Ligaments | Superior glenohumeral, middle glenohumeral, inferior glenohumeral, coracohumeral, transverse humeral | | Innervation | Subscapular nerve (joint); suprascapular nerve, axillary nerve, lateral pectoral nerve (joint capsule) | | Blood supply | Anterior and posterior circumflex humeral, circumflex scapular and suprascapular arteries | | Movements | Flexion, extension, abduction, adduction, external/lateral rotation, internal/medial rotation and circumduction | | Rotator cuff muscles | Supraspinatus, infraspinatus, teres minor, subscapularis | | | Mnemonic: Rotator cuff SITS on the shoulder | en/shoulder_joint.txt Last modified: 2023/06/21 10:21by 127.0.0.1