Author: Dr Peter de Souza
Last modified: 20 November 2022

The flexor digitorum longus is one of the muscles of the deep group within the posterior compartment of the leg.

The leg is comprised of anterior, lateral and posterior compartments. The posterior (flexor) compartment consists of two groups of muscles: a superficial group and a deep group, which are separated by a deep fascial layer.

Muscles of the superficial group within the posterior compartment of the leg

Muscles of the deep group within the posterior compartment of the leg

Origin

  • Medial side of posterior surface of the tibia

Insertion

  •  Plantar surfaces of bases of distal phalanges of the lateral four toes

Action

  • Flexes lateral four toes

Innervation

  • Tibial nerve: S2, S3

Blood Supply

  • Posterior tibial artery