Finger MCP flexion/extension ROM is measured. Which option correctly describes the patient position, stabilization, and goniometer placement?

• A. Position: Sitting with forearm/hand resting, neutral wrist and MCP joints; Stabilize: Metacarpal to prevent wrist motion (NOT MCP joints); Fulcrum: dorsal aspect of the MCP joint; Stationary arm: dorsal midline of metacarpal; Moving arm: dorsal midline of proximal phalanx
• B. Position: Sitting with forearm/hand resting, neutral MCP joints; Stabilize: Metacarpal to prevent MCP motion; Fulcrum: dorsal aspect of the MCP joint; Stationary arm: dorsal midline of proximal phalanx; Moving arm: dorsal midline of metacarpal
• C. Position: Sitting with forearm/hand resting, neutral wrist and MCP joints; Stabilize: Metacarpal to prevent wrist motion (NOT MCP joints); Fulcrum: dorsal aspect of the MCP joint; Stationary arm: dorsal midline of metacarpal; Moving arm: dorsal midline of proximal phalanx
• D. Position: Sitting with forearm/hand resting, neutral wrist and MCP joints; Stabilize: Metacarpal to prevent wrist motion (NOT MCP joints); Fulcrum: dorsal aspect of the MCP joint; Stationary arm: ventral midline of metacarpal; Moving arm: dorsal midline of proximal phalanx

Answer: (C)

When measuring MCP joint flexion/extension, the aim is to isolate motion at the metacarpophalangeal joint. To do that, stabilize the metacarpal (the proximal bone) to prevent any movement from the wrist or carpometacarpal area, and let the proximal phalanx move relative to it. Place the goniometer’s axis right over the MCP joint on its dorsal aspect, then align the stationary arm with the dorsal midline of the metacarpal and the moving arm with the dorsal midline of the proximal phalanx. The patient sits with the forearm supported and the wrist in a neutral position, starting with the MCP joints neutral.

This setup yields a true measurement of MCP ROM without contribution from wrist or other joints. The other configurations would misplace the arms or stabilize the wrong segment, leading to an inaccurate reading or movement being attributed to the wrong joint.