The patient may present with:
(1) loss of function in or instability of the shoulder when the arm is elevated
(2) sudden paralyzing pain and weakness while throwing
(3) sense of the arm "going dead"
(4) deterioration in performance when the arm is elevated
Any pain tends to be of short duration.
Features:
(1) There is a definite history of forceful overextension of the elevated and overly rotated arm, which may include a fall on an outstretched arm or overuse injury.
(2) Shoulder pain and instability can be reproduced:
(2a) when the arm is in use overhead (tennis serving, ball throwing, etc).
(2b) when forward pressure is applied to the posterior humeral head with the arm elevated and externally rotated (apprehension test)
(2c) when forward pressure is applied to the posterior humeral head with the patient in forward flexion
(3) The shoulder does not give problems if the person is lifting or using the arm below shoulder level.
(4) There is a poor response to conservative therapy.
The patient:
(1) is usually a young athletic adult and may be well-muscled.
(2) may be discouraged and frustrated.
(3) may recoil when the arm is elevated or if throwing is attempted.
(4) has normal shoulder X-ray and laboratory tests.
Differential diagnosis
(1) other conditions associated with pain on elevation or rotation of the arm (adhesive capsulitis, brachial neuritis, calcific tendonitis, nerve impingement, rotator cuff tear, thoracic outlet syndrome, etc).
(2) joint laxity (loose joints)
