Which configuration correctly outlines wrist flexion/extension assessment, including stabilization and goniometer alignment?

• A. Position: Supine with 90 degree GHJ abduction and 90 degree elbow flexion; Stabilize: Radius and ulna to prevent supination or pronation; Fulcrum: lateral aspect of wrist over the triquetrum; Stationary Arm: lateral midline of ulna, using olecranon and ulnar styloid process for ref; Moving Arm: lateral midline of 5th metacarpal
• B. Position: Supine; Stabilize: radius; Fulcrum: center of wrist; Stationary Arm: along ulna; Moving Arm: along metacarpals
• C. Position: Prone; Stabilize: forearm; Fulcrum: ulnar styloid; Stationary Arm: along radius; Moving Arm: along hand
• D. Position: Sitting; Stabilize: elbow; Fulcrum: radial styloid; Stationary Arm: along radius; Moving Arm: along hand

Answer: (A)

Measuring wrist flexion and extension with a goniometer relies on immobilizing the forearm, using a clear axis at the wrist, and aligning the instrument with reliable anatomical landmarks. The best configuration stabilizes the radius and ulna to prevent forearm rotation, places the fulcrum over a wrist bone representative of the radiocarpal joint (the triquetrum on the ulnar side), uses a stationary arm along the ulna (referencing the olecranon and ulnar styloid), and guides the moving arm along the midline of the 5th metacarpal. This setup ensures the reading captures true wrist motion rather than compensations from forearm or shoulder movements and keeps the measurement consistent across trials.

Other configurations either locate the axis inaccurately (such as at the center of the wrist or the radial styloid), fail to adequately stabilize the forearm (allowing pronation/supination or elbow movement to affect the angle), or use less appropriate reference lines (like alignment with the radius for the stationary arm). These issues can introduce error and make the reading reflect more than just wrist motion.