Flexor Hallucis Longus

The Flexor Hallucis Longus Muscle

The flexor hallucis longus (FHL) muscle is located within the deep compartment of the posterior leg. It is situated on the lateral side of this compartment, which can be slightly counterintuitive due to its attachment away from the great toe.

Attachments

The FHL originates from the posterior surface of the fibula and connects to the plantar surface of the phalanx of the great toe.

Actions

When the FHL is stimulated, it works to flex the great toe.

Innervation

The tibial nerve is the nerve responsible for the innervation of the FHL.

Blood Supply

The posterior tibial artery supplies the FHL with blood.

Figure 2 - Muscles in the Deep Layer of the Posterior Leg

• In this figure, the flexor hallucis longus is labeled on the medial side of the posterior leg.
• It is situated above the flexor digitorum longus (FDL) and flexor hallucis brevis (FHB) muscles.
• The FHL is encircled by the peroneus brevis (PB) and peroneus longus (PL) muscles.
• Its muscle fibers extend downwards from their attachment on the fibula to their connection with the great toe.

The flexor hallucis longus is a deep muscle in the posterior leg that plays an important role in flexing the great toe. Its origin from the posterior surface of the fibula and attachment to the plantar surface of the great toe phalanx allows it to perform this action. The tibial nerve is responsible for its innervation while the posterior tibial artery supplies the muscle with the blood it needs to function. Understanding the anatomy of the posterior leg and its muscles is critical for health professionals.