What best describes secondary shoulder impingement?

• A. A type of impingement occurring from joint degeneration
• B. A condition resulting from a tear in the rotator cuff
• C. A relative impingement occurring due to rotator cuff weakness
• D. An acute condition following an injury

Answer: (C)

Secondary shoulder impingement is characterized as a condition that arises from a relative impingement due to weakness or dysfunction in the rotator cuff muscles. In this scenario, when the rotator cuff is weak, it fails to effectively stabilize the humeral head within the glenoid cavity during shoulder movements, leading to kinematic abnormalities. These changes can result in the humeral head translating upward excessively and potentially impinging on the subacromial structures as the arm elevates or rotates.

This type of impingement is often seen in individuals who may not have structural changes or degenerative conditions but instead have muscle imbalances or weakness that compromise shoulder mechanics, leading to pain and dysfunction. Addressing the underlying weakness of the rotator cuff is crucial in the rehabilitation process to help restore proper biomechanics and alleviate symptoms associated with secondary shoulder impingement.