History
Taking a careful and detailed history greatly aids the physician in the diagnosis of swimmer's shoulder. The adolescent or teenaged swimmer often presents with a history of a recent growth spurt, an increase in the level of training and competition, or both.
Pain associated with swimmer's shoulder has the following characteristics:
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The pain is similar to that of rotator cuff pain. It is often poorly localized and felt to be deep within the shoulder.
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Initially, the pain is noted only during or immediately after swimming.
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On occasion, the pain can be associated with a particular position or phase of the stroke. A painful click or catch during the recovery phase of any overhand stroke suggests the possibility of a glenoid labral tear.
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As the athlete tries to swim "through the pain," it may worsen to the point where it affects nonswimming shoulder activities and might eventually be present at rest or at night.
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When the athlete finally stops swimming because of the pain, the condition often improves, but it recurs with a return to swimming if the rotator cuff has not been specifically restrengthened.
Physical Examination
Ask the patient to localize the pain. They may describe the pain as being deep, localized to the posterior aspect of the shoulder. Less commonly, they localize the pain anteriorly or at the deltoid insertion area of the upper arm. Pain characterized as such is consistent with rotator cuff tendinitis, the most common underlying cause of pain in swimmer's shoulder.
Observe both shoulders for any asymmetry, particularly in scapular position, or rotator cuff muscle mass (atrophy). Test the following shoulder features:
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Range of motion (ROM)
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Strength
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Stability
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Joint laxity
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Possible labral tear
Range of motion
Check the ROM of both shoulders, comparing one side to the other. The author typically measures the following:
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Forward flexion and/or abduction (> 180°, combined glenohumeral joint and scapulothoracic motion)
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Glenohumeral joint abduction (> 90°, measured by stabilizing the scapula with one hand, while abducting the glenohumeral joint alone)
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Abducted external rotation (> 90°, measured with the shoulder in 90° of abduction, with the elbow flexed)
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Abducted internal rotation (> 90°, same technique as abducted external rotation)
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Maximum internal rotation (thoracic vertebrae T4-T6, measuring combined glenohumeral joint and scapulothoracic motion by having the patient reach up his/her spine with the thumb)
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In most swimmers, both internal rotation (IR) and external rotation (ER) are greater than in the general population.
Shoulder strength
Assess the strength of the rotator cuff by resisting internal rotation (subscapularis) and external rotation (infraspinatus, teres minor) with the shoulder in the neutral position (at the side) and the elbow flexed to 90°.
Assess the strength of supraspinatus using the Jobe test position, with resisted shoulder elevation with the arms extended, internally rotated, and positioned in the scapular plane (approximately 30-45° anterior to the coronal plane). If weakness is apparent, retest the supraspinatus in the same arm position except with the arms externally rotated (ie, thumbs pointing upwards).
Assess the strength of the subscapularis with the subscapularis lift-off test. Perform this test by placing the shoulder in internal rotation with the back of the patient's hand against the small of the back. The patient attempts to lift hand away from back against the examiner's resistance.
Early on, the above tests may only produce pain. In advanced cases, however, weakness in the involved muscle—most commonly, the supraspinatus—may be noted.
Shoulder stability
Perform a shoulder apprehension test by placing the shoulder in maximum abduction and external rotation (90-90 position) while applying an anteriorly directed force to the shoulder from behind in an attempt to elicit a feeling of apprehension or instability. This test typically elicits some discomfort but no apprehension or sense of instability in most swimmers.
Perform anterior and posterior drawer tests of the humerus both in neutral with the patient sitting, and supine with the arm abducted 90°, while axially loading the glenohumeral joint (load and shift test). Compare with the opposite shoulder.
Most swimmers have a mild-to-moderate increase in shoulder laxity, indicating multidirectional laxity. Occasionally, this can lead to symptomatic instability, in which the swimmer complains of the shoulder subluxing or shifting with use.
Shoulder laxity
Assess inferior laxity by identifying the presence of a sulcus sign. This is completed by pulling the arm inferiorly, while checking for a gap or sulcus between the humeral head and lateral edge of the acromion, indicating inferior subluxation of the humeral head. This is graded as follows:
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Grade 1 - Less than 1 finger breadth (< 1 cm)
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Grade 2 - One finger breadth (1-2 cm)
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Grade 3 - Greater than 1 finger breadth (> 2 cm)
Compare results with the opposite shoulder. Laxity should be similar, except following unilateral traumatic injury.
Check for generalized ligamentous laxity (GLL) in other joints (eg, hyperextension at elbows and knees, thumb to forearm test, middle finger hyperextension to forearm). Generalized ligamentous laxity indicates a significant amount of inherent joint laxity related to the individual's collagen composition and is more commonly found in females than males. Multidirectional instability (MDI) is more difficult to manage in the presence of GLL.
Labral tear
A labral tear is suggested when a painful click is noted during the recovery phase of any overhand stroke. Often, the swimmer can reproduce this click during the exam.
The O'Brien test can suggest a superior labral tear, or the so-called SLAP (superior labrum anterior and posterior) lesion. Have the athlete resist a downward force with the arm extended in the forward flexed position, adducted 15° toward the midline, with the shoulder in maximal internal rotation (thumb pointing down). Pain produced with this maneuver and relieved with the arm externally rotated suggests a SLAP lesion.
