Biomechanics of the Shoulder and Pitching （生物力学的肩膀和俯仰）.pdfVIP

Biomechanics of the Shoulder and Throwing Shoulder Anatomy • Most mobile joint in the body – Ball-and-socket joint • 3 bones connected by muscles, ligaments tendons – Clavicle – Humerus – Scapula Range of Motion • 6 degrees of freedom • Flexion – Elevation in the sagittal plane • Abduction – Elevation in the coronal plane • Rotation – Internal / external: Forearm moving in transverse plane 3 Articulations • Acromioclavicular • Glenohumeral • Scapulothoracic •AC: Restrains both rotation and posterior translation of clavicle Cocroco-acromial, coroco-clavicular and acromio-clavicular ligaments /ligaments.htm Sternoclavicular • Links upper extremity directly to thorax – Fibrocartilage disc between the sternum and the clavicle • shock absorber • Held together by strong ligaments Glenohumeral • 4 glenohumeral ligaments, connect the humerus to the glenoid – superior, middle, inferior and posterior • Inferior glenohumeral ligament splits into a front and a back half. – These act like a hammock to support the humeral head • Dislocation inferiorly anterior most common in young people /ligaments.htm Scapulothoracic • Bone-muscle-bone articulation between the scapula and thorax • Involves gliding of the scapula on the posterior aspect of the thorax • The subscapularis and the serratus anterior glide along one another •