Compartments of the Leg

Posterior Compartment

Deep Posterior Compartment

Muscles:

Flexor Digitorum Longus

Flexes lateral four digits

PF ankle

Supports longitdunial arches of foot

Subtopic

Flexor Hallucis Longus

Flexes great toe at all joints

weakly PF ankle

Supports medial longitudinal arch of foot

Superficial Posterior Compartment

Muscles:

Gastrocnemius

Plantarflexes ankle when knee is extended

Raises heel during walking

Flexes leg at knee joint

Soleus

Plantarflexes ankle independent of position of knee

Steadies leg on foot

Plantaris

Weakly assists gastroc in PF ankle

Flexor Retinaculum

Anterior Compartment

Muscles:

Tibialis Anterior

Dorsiflexes ankle and inverts foot

Extensor Digitorum Longus

Extends lateral four digits and dorsiflexes ankle

Extensor Hallucis Longus

Extends great toe and dorsiflexes ankle

Innervation:

Deep Fibular Nerve

Anterior Tibial Artery

Anterior Tibial Vein

Retinaculum

Superior/ Inferior External Retinaculum

Lateral Compartment

Muscles:

Fibularis Brevis

Fibularis Longus

Innervation:

Superficial Fibular Nerve

Fibular Artery Branch

Retinaculum

Superior/Inferior Retinaculum

Innervation

Tibial Nerve

Posterior Tibial Artery

Posterior Tibial Vein

Fibular Vein

Fibular Artery

Fibularis Tertius

Dorsiflexes ankle and aids in eversion of foot

Tibialis Posterior

PF ankle; inverts foot

Action

Everts foot and weakly plantarflexes ankle

Clinical Relevance

Footdrop is a clinical sign indicating paralysis of the muscles in the anterior compartment of the leg. It is most commonly seen when the common fibular nerve (from which the deep fibular nerve arises) is damaged.

In footdrop, the muscles in the anterior compartment are paralysed. The unopposed pull of the plantarflexor muscles (found in the posterior leg) produces permanent plantarflexion.