Which muscle is primarily engaged in the hook grip used when carrying groceries?

Which muscle is primarily engaged in the hook grip used when carrying groceries?

• A. Flexor digitorum profundus
• B. Flexor digitorum superficialis
• C. Extensor digitorum
• D. Flexor pollicis longus

Answer: (A)

Hook grip relies on curling the fingers tightly around the object, which is driven mainly by the deepest finger flexor. The flexor digitorum profundus provides the strong flexion at the distal joints (DIP) needed to flex the fingertips and anchor the grasp around the grocery handle. The flexor digitorum superficialis also helps by bending the middle joints (PIP), but it can’t flex the DIP joints, so it can’t create the same tight hook by itself. The extensor digitorum would straighten the fingers, counteracting the grip, and the flexor pollicis longus mainly aids thumb flexion rather than the primary hook formed by the fingers. So, the primary muscle involved is the flexor digitorum profundus.

Hook grip relies on curling the fingers tightly around the object, which is driven mainly by the deepest finger flexor. The flexor digitorum profundus provides the strong flexion at the distal joints (DIP) needed to flex the fingertips and anchor the grasp around the grocery handle. The flexor digitorum superficialis also helps by bending the middle joints (PIP), but it can’t flex the DIP joints, so it can’t create the same tight hook by itself. The extensor digitorum would straighten the fingers, counteracting the grip, and the flexor pollicis longus mainly aids thumb flexion rather than the primary hook formed by the fingers. So, the primary muscle involved is the flexor digitorum profundus.