Lower Leg

Muscles of the Anterior Leg

• Dorsiflexors of ankles and extensors of toesreside in anterolateral compartment as the tibia fills the

anteriomedial area• Anterior tibialis:crosses to the medial arch of foot & is

an invertor of foot, as well as dorsiflexor of ankle• Extensor digitorum longus:primary function is to extend

toes II-V (lift them up). It also performs dorsiflexion of the ankle and eversion of the foot.

• Extensor Hallucis longus [hallux = great toe]:extends the great toe (pulls it up), but also assists with dorsiflexion and inversion of the ankle.

• Peroneus tertius – small muscle, absent in some people. dorsiflexion and eversion of the ankle.

Tibialis Anterior

Extensor Digitorum

Longus

Peroneus Tertius

Extensor Hallucis

Longus

Muscles of the Lateral Leg

• Evertors of the foot– Tendons pass to the lateral margin and

underside of the foot• Help to prevent excessive inversion

• Peroneus longus: ankle plantarflexion and eversion

• Peroneus brevus:does not go under the foot. It also performs plantar flexion and eversion of

the ankle.

Muscles of the Posterior leg• Gastrocnemius: plantarflexor ankle & flexes knee• Soleus: plantarflexor• Plantaris:weakly plantarflexes the ankle joint &flex the knee

joint. Its function is so minimal that its long tendon can readily be harvested for reconstruction elsewhere with little functional deficit

• Popliteus: relatively small muscle at the back of the tibia. Its tendon winds gradually upward around the lateral side of the knee to attach to the femur just above the outside of the knee on the lateral epicondyle.

• Flexor hallucis longus• Flexor digitorum longus:Flexes distal phalanges of lateral

four toes and foot at ankle. Supports lateral longitudinal arch • Tibialis posterior: primary invertor & plantarflexor

http://www.therunningdoctor.com/achilles_fig.jpg