You are measuring wrist radial deviation. Which option correctly specifies the patient position, stabilization, and goniometer placement?

• A. Position: Supine w/ shoulder abducted 90 degrees and elbow flexed 90 degrees; Stabilize: Radius and ulna to prevent supination or pronation and elbow flexion beyond 90 degrees; Fulcrum: dorsal aspect over capitate; Stationary arm: dorsal midline forearm; Moving arm: dorsal midline 3rd metacarpal
• B. Position: Supine w/ shoulder abducted 90 degrees and elbow flexed 90 degrees; Stabilize: Radius and ulna to prevent supination or pronation and elbow flexion less than 90 degrees; Fulcrum: dorsal aspect over capitate; Stationary arm: dorsal midline forearm; Moving arm: dorsal midline 3rd metacarpal
• C. Position: Prone with arm at side; Stabilize: Humerus to prevent rotation; Fulcrum: dorsal aspect over capitate; Stationary arm: dorsal midline forearm; Moving arm: dorsal midline 3rd metacarpal
• D. Position: Supine with shoulder abducted 90 degrees and elbow flexed 90 degrees; Stabilize: Radius and ulna to prevent supination or pronation and elbow flexion beyond 90 degrees; Fulcrum: dorsal aspect over capitate; Stationary arm: dorsal midline forearm; Moving arm: ventral midline of 3rd metacarpal

Answer: (A)

Measuring wrist radial deviation accurately hinges on isolating the wrist while keeping the forearm and elbow from moving. The ideal setup fixes the forearm in place and uses a fixed, consistent pivot at the wrist, with the alignment of the arms following the dorsal surfaces of the radius–ulna and the 3rd metacarpal so the goniometer tracks true carpal motion.

In this setup, the person lies supine with the shoulder abducted 90 degrees and the elbow flexed 90 degrees. This position stabilizes the limb and makes it easy to control the forearm’s orientation. Stabilizing the radius and ulna prevents pronation or supination and also prevents the elbow from flexing beyond 90 degrees, which could introduce additional movement that skews the reading. The fulcrum is placed on the dorsal aspect of the wrist over the capitate, which is the central bony point of wrist motion for this measure. The stationary arm runs along the dorsal midline of the forearm, providing a stable reference, and the moving arm traces the dorsal midline of the 3rd metacarpal to follow the direction of the movement.

Other configurations would allow unwanted forearm or elbow motion, use a less appropriate landmark, or orient the arms in a way that doesn’t reflect the true wrist motion, leading to unreliable results.