2. ROM and GIRD assessment
After inspection and palpation, the shoulder should be ranged in all relevant planes of motion. Our standard examination includes forward elevation in the frontal and scapular planes, along with external rotation at the side and at 90° of abduction, as well as internal rotation behind the back with documentation of the highest spinal level that the patient can reach. This examination may be performed with the patient upright, but supine positioning can help stabilize the scapula and provide more accurate views of motion. Deficits of internal rotation may be a common finding in overhead athletes, and the degree of this deficit should be quantitatively noted.
Bony and soft-tissue remodeling of the shoulder (and associated structures) in the overhead athlete can lead to contracture of the posterior capsule. This contracture can cause excessive external rotation and subsequent decrease in internal rotation, leading to pain and anterior instability in the throwing shoulder.2 For precise measurements of the internal and external rotation arc, the scapula must be stabilized. This can be done with the patient supine on the examining table or seated upright with manual stabilization of the scapula by the examiner. Once the scapula is stabilized, the arc of internal and external rotation (with the arm in about 90° of abduction) can be measured with a goniometer, with maximum values obtained as the scapula begins to move along the posterior chest wall.2 The difference in internal rotation between the dominant and nondominant arms defines the extent of the athlete’s GIRD. Internal rotation can also be qualitatively assessed by having the athlete internally rotate each arm and reach up the spine while the examiner notes the difference in level achieved. However, this does not provide a quantitative assessment of the patient’s GIRD.
In general, the sum of the internal and external rotation arcs on the 2 sides should be symmetric. Consequently, in GIRD, excessive external rotation is balanced by decreased internal rotation. Symptomatic GIRD may be present when there is more than 25° of discrepancy in internal rotation between the athlete’s dominant and nondominant arms.2 The goal is to reduce this discrepancy to less than 20°.
3. Internal impingement: rotator cuff and labrum
In overhead athletes, an intricate relationship involving rotator cuff, labrum, and biceps tendon allows for efficient, pain-free force delivery at the shoulder. However, because of the significant external rotation and abduction required in the overhead motion, there may be internal impingement of the posterosuperior rotator cuff (infraspinatus and posterior aspect of supraspinatus) between the posterior labrum and the greater tuberosity. Detailed examination of these structures must be performed in any assessment of an overhead athlete. Symptomatic patients may complain of pain during the throwing cycle, particularly in late cocking and early acceleration.
The modified relocation examination is a common maneuver to detect internal impingement.3 In this examination, the patient’s arm is brought into a position of maximal external rotation and abduction mimicking that found in late cocking or early acceleration. In this position, a patient with internal impingement complains of pain in the posterior shoulder. A posteriorly directed force on the humerus relieves this pain.
There are also many examinations for detecting labral pathology, specifically a SLAP (superior labrum, anterior to posterior) lesion, which is commonly found in patients with internal impingement. One commonly tested maneuver is the O’Brien active compression test (Figures 2A, 2B), which has excellent sensitivity and specificity in detecting type II SLAP lesions.4 In this examination, the patient holds the arm in about 15° of adduction and 90° of forward elevation. A downward force is applied with the forearm pronated and subsequently supinated. If pain is noted on the force applied to the pronated arm, and if this pain decreases in the supinated examination, the test is positive for labral pathology.
Anterior instability is routinely found in these patients. Translation is measured with the anterior load and shift test. Anterior translation is tested with the patient supine, with the arm in abduction and external rotation, and with the examiner placing an anteriorly directed force on the humeral head. Translation is compared with the contralateral side and graded on a 3-point scale (1+ is translation to glenoid rim, 2+ is translation over glenoid rim but reduces, 3+ is translation over glenoid and locking). We also use the anterior release test, in which the patient is supine, the arm is brought into abduction and external rotation, and the examiner places a posteriorly directed force on the humeral head. When the examiner removes this force, the patient notices symptoms of instability caused by subluxation (Figures 3A, 3B).
