Which muscle action is extension at finger joints and the wrist?

• A. Abduction at Hip
• B. Depression of Ribs
• C. Extension at Finger Joints and the Wrist
• D. Flexion at Elbow

Answer: (C)

Extension at finger joints and the wrist is carried out by the extensor muscles of the forearm. When these muscles contract, they pull the tendons that cross the finger joints, straightening the fingers (extending the metacarpophalangeal and interphalangeal joints) and also extending the wrist. This combined extension is the opposite of bending, or flexion, at those joints.

The other options describe movements at different joints or in the opposite direction: abduction at the hip moves the leg away from the body's midline, depression of the ribs is a breathing action, and flexion at the elbow bends the elbow rather than straightening it.