Radial nerve motor function includes extension at which joints?

Radial nerve motor function includes extension at which joints?

• A. Shoulder abduction and wrist extension
• B. DIP joints extension
• C. Elbow, wrist, and MCP joints
• D. Thumb opposition

Answer: (C)

Radial nerve motor function centers on extending the joints of the arm and hand. It supplies the triceps to straighten the elbow, the extensor muscles to lift the wrist, and the extensor digitorum (along with related extensors) to extend the metacarpophalangeal joints of the fingers. That combination—elbow, wrist, and MCP extension—is the classic pattern for what the radial nerve does. Shoulder abduction is primarily done by the axillary nerve, thumb opposition by the median nerve, and DIP extension involves the finger extensor mechanism but is not the primary radial nerve responsibility. So the movement pattern that best reflects radial nerve motor function is extension at the elbow, wrist, and MCP joints.

Radial nerve motor function centers on extending the joints of the arm and hand. It supplies the triceps to straighten the elbow, the extensor muscles to lift the wrist, and the extensor digitorum (along with related extensors) to extend the metacarpophalangeal joints of the fingers. That combination—elbow, wrist, and MCP extension—is the classic pattern for what the radial nerve does. Shoulder abduction is primarily done by the axillary nerve, thumb opposition by the median nerve, and DIP extension involves the finger extensor mechanism but is not the primary radial nerve responsibility. So the movement pattern that best reflects radial nerve motor function is extension at the elbow, wrist, and MCP joints.