The lumbricals of the foot are a group of intrinsic muscles within the second layer of the plantar muscles of the foot.
The intrinsic muscles of the foot consist of one intrinsic muscle on the dorsal aspect of the foot (the extensor digitorum brevis), and 4 layers of muscles on the plantar aspect of the foot:
- 1st layer: abductor hallucis, flexor digitorum brevis, abductor digiti minimi
- 2nd layer: quadratus plantae, lumbricals
- 3rd layer: flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis
- 4th layer: dorsal interosseri, plantar interossei
Origin
- Tendons of flexor digitorum longus
Insertion
- Medial extensor expansion hoods of toes 2 to 5
Action
- Flexion of metatarsophalangeal joint
- Extension of interphalangeal joints
Innervation
- Medial plantar nerve from tibial nerve: S2, S3
Blood Supply
- Plantar metatarsal artery