Tibialis anterior muscle

The tibialis anterior muscle is a muscle in the anterior compartment of the leg. It originates from the lateral condyle and the upper two-thirds of the lateral surface of the tibia, as well as the interosseous membrane and deep fascia of the leg. Its tendon inserts onto the medial cuneiform and the base of the first metatarsal. It is responsible for dorsiflexion and inversion of the foot.

The tibialis anterior is a long, fusiform muscle situated on the lateral aspect of the tibia, forming the most superficial and medial component of the anterior compartment of the leg.

Origin

• Lateral condyle of the tibia

• Upper two-thirds (or upper half) of the lateral surface of the tibial shaft

• Anterior surface of the interosseous membrane

• Deep surface of the fascia cruris (deep fascia of the leg)

• Intermuscular septum separating it from extensor digitorum longus

Insertion

The tibialis anterior muscle descends vertically, and its long tendon passes beneath the extensor retinaculum before coursing toward the medial side of the leg and foot, where it ultimately inserts onto the:

• Medial cuneiform (medial and inferior surfaces), and

• Adjacent surface of base of the first metatarsal bone

Innervation

Deep fibular (peroneal) nerve (root value: L4–L5)

Blood supply

Anterior tibial artery and its branches

Actions

• Dorsiflexion of the ankle joint

• Inversion of the foot at the subtalar and midtarsal joints

• Contributes to stabilization of the medial longitudinal arch