Anterior region of leg

The anterior region of leg typically corresponds to the anterior leg compartment.

Fascia and skin:

• Similar to other leg regions, the muscles, ligaments, and neurovasculature of the anterior region of leg are enveloped by skin, superficial, and deep fascial coverings.

• The deep fascia thickens around the ankle joint to form an extensor retinaculum, which supports the long tendons of the anterior leg muscles to prevent them from bowstringing during ankle movements. There are two additional retinacula in the ankle region: the peroneal retinaculum (for the lateral leg compartment) and the extensor retinaculum (for the anterior leg region).

Musculature:

• Muscles of the anterior region of leg include the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and fibularis (peroneus) tertius. They originate from the tibia and fibula, cross over the ankle joint, and insert into the foot. These muscles are responsible for dorsiflexion at the ankle joint. It is worth noting that the muscles for plantar flexion (posterior leg region) are larger than the muscles for dorsiflexion (anterior leg region) since plantar flexion involves lifting the entire body while dorsiflexion only involves lifting the foot.

• The tibialis anterior lies medially and contributes to foot inversion, while the peroneus tertius lies on the lateral side of the foot and produces foot eversion. Inversion and eversion occur at the intertarsal joints, unlike plantar and dorsiflexion,.

Neurovasculature:

• The sciatic nerve usually divides in the upper part of the popliteal fossa into the tibial and common fibular (common peroneal) nerve branches. The common fibular nerve (common peroneal nerve) continues around the neck of the fibula and enters the lateral leg compartment, where it further divides into the superficial and deep fibular (peroneal) nerves. The deep fibular nerve innervates (a) all muscles of the anterior region of leg, (b) extensor digitorum brevis (located on the dorsum of the foot), and (c) the skin between the great and second toes, where the nerve terminates.

• The anterior region of leg receives its blood supply from the anterior tibial vessels.