After the Minnesota Vikings failed to win the 1974 Super Bowl, I received a request to rehabilitate Fran Tarkenton's throwing shoulder. The Humerus is the shoulder joint's bone of interest.
Humeral heads articulate with scapulas' glenoid fossas.
Glenoid fossas have very shallow sockets. While shallowness decreases shoulder joint stability, shallowness increases shoulder joints' motion ranges. Glenoid labrums attach to glenoid fossas' rims and around humeral heads' rims. Glenohumeral ligaments anteriorly stabilize humeral heads. Coracohumeral ligament suspend humeral heads from above and limit humeral rotations.