Secondary Subacromial Impingement Syndrome typically results from what underlying condition?

• A. Rotator cuff tears
• B. Underlying instability of the glenohumeral joint
• C. Capsular fibrosis
• D. Mechanical injury from sports

Answer: (B)

Secondary subacromial impingement syndrome occurs primarily due to underlying instability of the glenohumeral joint. This instability can lead to poor mechanics of the shoulder girdle, resulting in abnormal movement patterns and increased wear on the structures within the subacromial space. When the glenohumeral joint is unstable, the humeral head may not stay centered in the glenoid during arm movements, which can increase the likelihood of compression and irritation of the rotator cuff tendons and the subacromial bursa against the overlying acromion.

In this context, the presence of glenohumeral instability can lead to compensatory mechanisms and altered shoulder mechanics, which are crucial contributors to the development of secondary impingement. This condition is often seen in athletes or individuals with activities that require repetitive overhead motions, where joint stability is challenged.

Understanding the role of glenohumeral joint instability in secondary subacromial impingement syndrome helps healthcare professionals target their interventions, such as strengthening shoulder stabilizers and improving overall joint mechanics, to alleviate symptoms and improve functional outcomes.