Introduction Function allows scapular motion against the rib cage Osteology not a true joint; actually an articulation between the scapula and the thorax is a sliding "joint" between medial border of scapula and ribs 2-7 resting position angulation (although these are variable even in healthy adults) anteriorly 10-20° internally rotated 30°-45° from the coronal plane upward tilt of 3° Biomechanics Motion primary motion elevation & depression movement up and down along the rib cage secondary motions protraction & retraction movement away from or toward the vertebral column upward & downward rotation upward rotation with arm elevation downwared rotation with arm returning to side from raised position internal & external rotation anterior & posterior tipping shoulder abduction the ratio of glenohumeral motion to scapulothoracic motion is 2:1 GH does 120°, then ST does 60° Stability 17 different muscles attach to or originate from the scapula trapezius serratus anterior deltoid latisimus dorsi levator scapulae rhomboid major rhomboid minor omohyoid - inferior belly pectoralis minor teres major teres minor triceps brachii biceps brachii coracobrachialis infraspinatus subscapularis supraspinatus Clinical Scapulothoracic dissociation Scapular winging Scapulothoracic dyskinesis
Scapulothoracic Joint introduction OBC What is its main function? Function allows scapular motion against the rib cage Show Bullets