Which of the following describes the empty can test protocol?

• A. Arms are elevated to 60 degrees in scapular plane with palms forward, and upward resistance is applied.
• B. Arms are elevated to 90 degrees in scapular plane, externally rotated with thumbs up, and upward resistance is applied.
• C. Arms are elevated to 120 degrees in frontal plane with thumbs down, and downward resistance is applied.
• D. Arms are elevated to 90 degrees in scapular plane, internally rotated so thumbs point down, and downward resistance is applied.

Answer: (D)

The empty can test isolates the supraspinatus by placing the shoulder in a specific vulnerable position and asking the person to resist downward force. Elevate the arm about 90 degrees in the scapular plane (roughly between the frontal and sagittal planes) and rotate the arm so the thumb points downward (internal rotation). The examiner then applies downward pressure as the person resists. If this position reproduces pain or weakens the resisted effort, it suggests supraspinatus tendon pathology.

Other options don’t fit because they modify key elements: the plane of elevation, the rotation of the arm, or the direction of resistance. The correct approach uses 90 degrees of abduction in the scapular plane with internal rotation (thumbs down) and downward resistance.