In the case of suspected secondary shoulder impingement, what does a positive Speed's test indicate?

• A. Increased flexibility of the shoulder
• B. Weakness in the biceps tendon
• C. Upward migration of the humerus due to instability
• D. Positive response from the rotator cuff

Answer: (C)

A positive Speed's test is indicative of biceps tendon involvement, particularly assessing for tendinopathy rather than directly pinpointing instability. In the context of secondary shoulder impingement, the test demonstrates that there is concern for the integrity and position of the biceps tendon, which can be affected by the shoulder's kinematics and the position of the humeral head.

When the humerus migrates upward due to instability, particularly in the presence of underlying issues like scapular dyskinesis or rotator cuff weakness, there can be an increased risk of impingement for both the biceps tendon and the rotator cuff structures. The upward migration is a result of a poorly stabilized shoulder joint; thus, the Speed's test may show a positive result by eliciting pain or discomfort in alignment with this instability.

Understanding this dynamic helps in diagnosing conditions related to secondary shoulder impingement, as the underlying instability contributes to the symptomatic presentation during functional assessments like Speed's test.