I am a 17-year old All Star baseball pitcher. I've had trouble with my pitching arm dislocating because of an injury. I've been doing exercises for the shoulder and upper arms. What else can I do to keep this arm stable?

A recent study from the Orthopedic Biomechanics Laboratory at the Mayo Clinic in Rochester, Minnesota, offers some new information. The role of the deltoid muscle as a shoulder stabilizer was reported.

The deltoid is a muscle that makes up most of the bulk of your outer, upper arm. It's divided into three parts: anterior, middle, and posterior. The deltoid lifts the arm up. It also holds the head of the humerus (upper arm bone) against the glenoid (shoulder socket).

The researchers found that all three parts of the deltoid work equally to hold the shoulder and keep it from dislocating forwards. You're probably already strengthening the rotator cuff and biceps muscle. It may be adviseable to now strengthening exercises for the deltoid muscle.