Which nerve innervates the first lumbrical muscle? (Alternate phrasing)

Which nerve innervates the first lumbrical muscle? (Alternate phrasing)

• A. Tibial nerve
• B. Lateral plantar nerve
• C. Common fibular nerve
• D. Medial plantar nerve

Answer: (D)

The nerve supply pattern of the sole shows a division from the tibial nerve into medial and lateral plantar branches, and the first lumbrical is fed by the medial plantar nerve. This nerve supplies the medial group of intrinsic foot muscles, including abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and the first lumbrical, coordinating flexion at the metatarsophalangeal joint with extension at the interphalangeal joints. The remaining lumbricals receive innervation from the lateral plantar nerve. So the first lumbrical’s specific supply from the medial plantar nerve explains why that nerve is the correct answer.

The nerve supply pattern of the sole shows a division from the tibial nerve into medial and lateral plantar branches, and the first lumbrical is fed by the medial plantar nerve. This nerve supplies the medial group of intrinsic foot muscles, including abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and the first lumbrical, coordinating flexion at the metatarsophalangeal joint with extension at the interphalangeal joints. The remaining lumbricals receive innervation from the lateral plantar nerve. So the first lumbrical’s specific supply from the medial plantar nerve explains why that nerve is the correct answer.