Which statement best describes shoulder extension strength testing?

Which statement best describes shoulder extension strength testing?

• A. Move the arm anteriorly (flexion) against resistance, with thoracic stabilization.
• B. Move the arm posteriorly (extension) against resistance, with stabilization of the scapular region.
• C. Abduct the arm with resistance at the wrist.
• D. Extend the elbow against resistance at the biceps tendon.

Answer: (B)

Testing shoulder extension strength focuses on pulling the arm backward at the glenohumeral joint while keeping the shoulder girdle from moving. The best way to isolate this action is to have the scapular region stabilized so the movement comes from the shoulder itself, not the trunk or scapulothoracic muscles. In practice, the arm is moved posteriorly against resistance, with the examiner placing the resistance on the distal arm and ensuring the scapula remains still. The primary movers here are the posterior deltoid, with contribution from muscles like the infraspinatus and teres minor, and to some degree latissimus dorsi and teres major. Why the other descriptions don’t fit: describing movement anteriorly against resistance targets shoulder flexion, not extension. Abducting the arm refers to moving it away from the body, a different plane of motion than extension. Finally, testing elbow extension involves the elbow joint (primarily the triceps), and resistance would be applied at the forearm or olecranon, not at the biceps tendon, so that does not describe shoulder extension.

Testing shoulder extension strength focuses on pulling the arm backward at the glenohumeral joint while keeping the shoulder girdle from moving. The best way to isolate this action is to have the scapular region stabilized so the movement comes from the shoulder itself, not the trunk or scapulothoracic muscles. In practice, the arm is moved posteriorly against resistance, with the examiner placing the resistance on the distal arm and ensuring the scapula remains still. The primary movers here are the posterior deltoid, with contribution from muscles like the infraspinatus and teres minor, and to some degree latissimus dorsi and teres major.

Why the other descriptions don’t fit: describing movement anteriorly against resistance targets shoulder flexion, not extension. Abducting the arm refers to moving it away from the body, a different plane of motion than extension. Finally, testing elbow extension involves the elbow joint (primarily the triceps), and resistance would be applied at the forearm or olecranon, not at the biceps tendon, so that does not describe shoulder extension.