Which nerve innervates the 2nd, 3rd, and 4th lumbricals?

Which nerve innervates the 2nd, 3rd, and 4th lumbricals?

• A. Medial Plantar Nerve
• B. Lateral Plantar Nerve
• C. Deep Fibular Nerve
• D. Tibial Nerve

Answer: (B)

In the sole, the lumbricals have distinct nerve supplies: the first lumbrical is innervated by the medial plantar nerve, while the second through fourth lumbricals are innervated by the lateral plantar nerve. The lateral plantar nerve is the larger terminal branch of the tibial nerve that supplies most intrinsic sole muscles, including the lumbricals 2–4, as well as interossei. The medial plantar nerve supplies the medial group of muscles (such as abductor hallucis, flexor digitorum brevis, and flexor hallucis brevis) and the first lumbrical. The deep fibular nerve innervates dorsum-foot muscles and does not supply the lumbricals, and the tibial nerve provides the trunk that splits into the medial and lateral plantar nerves, with the motor innervation for these lumbricals coming specifically from the lateral plantar nerve. Therefore, the nerve that innervates the 2nd, 3rd, and 4th lumbricals is the lateral plantar nerve.

In the sole, the lumbricals have distinct nerve supplies: the first lumbrical is innervated by the medial plantar nerve, while the second through fourth lumbricals are innervated by the lateral plantar nerve. The lateral plantar nerve is the larger terminal branch of the tibial nerve that supplies most intrinsic sole muscles, including the lumbricals 2–4, as well as interossei. The medial plantar nerve supplies the medial group of muscles (such as abductor hallucis, flexor digitorum brevis, and flexor hallucis brevis) and the first lumbrical. The deep fibular nerve innervates dorsum-foot muscles and does not supply the lumbricals, and the tibial nerve provides the trunk that splits into the medial and lateral plantar nerves, with the motor innervation for these lumbricals coming specifically from the lateral plantar nerve. Therefore, the nerve that innervates the 2nd, 3rd, and 4th lumbricals is the lateral plantar nerve.