A patient with shoulder pain has a positive drop arm test. What is the most likely diagnosis?

A patient with shoulder pain has a positive drop arm test. What is the most likely diagnosis?

• A. Peripheral neuropathy
• B. Shingles
• C. Broken clavicle
• D. Torn rotator cuff

Answer: (D)

The drop arm test targets the rotator cuff, especially the supraspinatus tendon. When the arm is abducted to about 90 degrees, the patient is asked to lower it slowly. If the arm cannot be controlled and suddenly drops or the patient has pain that prevents lowering, this is a positive sign. That pattern points to a tear in the rotator cuff, most often a supraspinatus tear, which weakens the ability to eccentrically control the descent from the abducted position. In contrast, peripheral neuropathy would produce more diffuse nerve-related weakness and sensory changes rather than a specific inability to control a 90-degree abduction; shingles would present with a dermatomal rash and neuropathic pain; a broken clavicle would show deformity and prominent swelling after trauma. Thus, a torn rotator cuff best explains a positive drop arm sign in a patient with shoulder pain.

The drop arm test targets the rotator cuff, especially the supraspinatus tendon. When the arm is abducted to about 90 degrees, the patient is asked to lower it slowly. If the arm cannot be controlled and suddenly drops or the patient has pain that prevents lowering, this is a positive sign. That pattern points to a tear in the rotator cuff, most often a supraspinatus tear, which weakens the ability to eccentrically control the descent from the abducted position.

In contrast, peripheral neuropathy would produce more diffuse nerve-related weakness and sensory changes rather than a specific inability to control a 90-degree abduction; shingles would present with a dermatomal rash and neuropathic pain; a broken clavicle would show deformity and prominent swelling after trauma. Thus, a torn rotator cuff best explains a positive drop arm sign in a patient with shoulder pain.