The patient presents with severe pain.  The arm is in slight abduction and external rotation and often supported by the opposite extremity.  There is a “squared-off” appearance to the affected shoulder due to the prominence of the acromion when the humeral head is anterior and inferior to the glenoid.  This is particularly noticeable in thin patients.  The patient cannot adduct or internally rotate at the glenohumeral joint without severe pain.

     A thorough neurovascular exam is important to assess for associated injuries, specifically the axillary and radial nerves. Axillary nerve function can be assessed by testing for sensation over the lateral aspect of the shoulder and with motor function of the teres minor and deltoid muscles (attempt shoulder abduction and look for contraction of deltoid muscle). The radial nerve can be assessed by asking the patient to extend the wrist and elbow and abducting the thumb.