In the case of a positive Adson's test, what is likely indicated?

• A. Disc herniation
• B. Potential neural entrapment by the scalene muscles
• C. Shoulder impingement
• D. Rotator cuff tear

Answer: (B)

A positive Adson's test is primarily associated with thoracic outlet syndrome, particularly indicating potential neural entrapment by the scalene muscles. This test is performed to assess the presence of neurovascular compression in the thoracic outlet, where the brachial plexus and subclavian vessels may be compressed by anatomical structures such as the scalene muscles.

When the arm is extended and the patient turns their head towards the tested side, a diminished or absent radial pulse suggests that the neurovascular bundle could be compromised, often due to tightness or hypertrophy of the scalene muscles. This compression can lead to neurological symptoms like pain, numbness, and tingling in the upper extremity due to irritation or entrapment of the nerves.

In contrast, other conditions such as disc herniations, shoulder impingement, or rotator cuff tears don't typically present with the symptoms or clinical findings that the Adson's test is designed to identify. Each of those conditions has its specific tests and signs that are more indicative of their respective pathologies. Thus, the association of a positive Adson's test reliably points toward the complications related to the scalene muscles and thoracic outlet syndrome.