 Overview
- not a true joint, instead a sliding joint between medial border of scapular and ribs 2-7
- functions to allow scapular motion against the rib cage
- resting position is angled anteriorly at 30° and an upward tilt of 3°
- Motion
- During shoulder abduction the ratio of glenohumeral motion to scapulothoracic motion is 2:1 (GH does 120°, then ST does 60°)
- Stability
- position fixed primarily by scapular muscle attachments
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