Empty can/Full can tests

Empty Can Test and Full Can Test are clinical examination procedures used in orthopedic and sports medicine to assess the integrity and function of the supraspinatus muscle and tendon, which are part of the rotator cuff in the shoulder. These tests help in diagnosing conditions such as rotator cuff tears or impingement syndrome.

Procedure

The Empty Can Test and Full Can Test are performed with the patient in a seated or standing position.

Empty Can Test

1. The patient elevates their arms to 90 degrees in the scapular plane (approximately 30 degrees anterior to the frontal plane of the body). 2. The patient then internally rotates the arm so the thumb is pointing downward, as if emptying a can. 3. The examiner applies downward pressure on the arm, and the patient resists the pressure.

A positive Empty Can Test is indicated by pain or weakness in the shoulder, suggesting a possible tear or impingement of the supraspinatus tendon.

Full Can Test

1. The patient elevates their arms to 90 degrees in the scapular plane, similar to the Empty Can Test. 2. However, in the Full Can Test, the patient externally rotates the arm so the thumb is pointing upward, as if holding a full can. 3. The examiner again applies downward pressure on the arm, and the patient resists.

A positive Full Can Test is indicated by pain or weakness, which may suggest a less severe injury compared to the Empty Can Test, as it places less stress on the supraspinatus tendon.

Interpretation

- A positive test indicates potential injury to the supraspinatus muscle or tendon. - Pain or weakness during these tests suggests rotator cuff pathology, specifically involving the supraspinatus tendon. - The Full Can Test is considered to be more specific for supraspinatus strength, as it isolates the muscle more effectively and reduces the impingement of the acromion on the tendon.

Clinical Significance

These tests are valuable tools in the physical examination of patients with shoulder pain. They help in differentiating supraspinatus pathology from other shoulder disorders. However, these tests should not be used in isolation for diagnosis. A comprehensive shoulder examination, including imaging studies when necessary, is important for an accurate diagnosis.

See Also

• Rotator cuff
• Shoulder examination
• Impingement syndrome
• Orthopedic examination