Once range of motion is determined, assess7:
- muscle power of the rotator cuff in abduction (for the supraspinatus muscle)
- resisted external rotation at the side of the body (the infraspinatus)
- resisted external rotation in abduction > 60° (the teres minor)
- resisted internal rotation (the subscapularis).
Specific tests for shoulder laxity and stability
It is important during the primary care follow-up examination to differentiate true instability and shoulder hyperlaxity, particularly in young, flexible patients (TABLE). Many of these patients present with painless hypermobility of the shoulder without true injury to the labrum or ligamentous structures. It might appear to the patient, or to family, that the shoulder is subluxating; however, the humeral head returns to a centered position on the glenoid in a hypermobile state—typically, without pain. Actual shoulder instability is defined as loss of the ability of the humeral head to re-center, accompanied by pain—pathology that is frequently associated with damage to the capsulolabral complex.
The load and shift test is used to assess anterior and posterior laxity. The patient is seated, and the forearm is allowed to rest on the thigh. Examination is performed using 1 hand to press anteriorly or posteriorly on the humeral head; the other hand is simultaneously positioned on the joint line to feel movement of the humeral head in relation to the glenoid (FIGURE 4).
The apprehension test is a common maneuver used to assess anterior shoulder instability. It is performed by positioning the affected arm to 90° external rotation and then elevating it to 90° abduction. Although this maneuver can be performed with the patient upright, it is beneficial to have them supine, to more easily control the arm (FIGURE 5). A positive test is noted when the patient reports a sensation of impending instability (apprehension), rather than pain alone.
Relocation test. When the apprehension test is positive, the supine position can be exploited to further perform the relocation test, in 2 stages (FIGURE 6):
- Apply a posteriorly directed force on the humeral head, which stabilizes the shoulder and typically alleviates symptoms.
- Release pressure quickly from the humeral head to assess recurrence of pain and apprehension as the humeral head snaps back against the anterior labrum.
Continue to: Combined, apprehension and relocation...