plantarflexors

Plantarflexors are a group of muscles that produce plantarflexion of the foot at the ankle, meaning they point the toes downward and decrease the angle between the sole and the back of the leg. They are essential for standing upright, walking, and especially for push-off during gait.

The primary plantarflexors form the back of the leg and include the gastrocnemius and the soleus, which join to form the strong Achilles (calcaneal) tendon that inserts on the calcaneus. The gastrocnemius also crosses the knee, so its effectiveness is influenced by knee position. The soleus is more of a postural muscle and is active during quiet standing. The plantaris is a small, variable muscle that can contribute modestly to plantarflexion. Additional muscles that assist with plantarflexion include the tibialis posterior, flexor digitorum longus, and flexor hallucis longus, which also play roles in toe movements. The fibularis (peroneus) longus and brevis provide eversion and add a contributing plantarflexion component.

Nerve supply and blood flow support their function. The gastrocnemius, soleus, plantaris, tibialis posterior, flexor digitorum longus, and flexor hallucis longus are innervated mainly by the tibial nerve. The fibularis longus and brevis are innervated by the common fibular (peroneal) nerve. The posterior tibial and peroneal arteries supply the region.

Clinically, reliable plantarflexion is important for a healthy gait. Weakness or injury—such as Achilles tendon rupture or tendinopathy—impairs push-off and balance. Assessment often involves resisted plantarflexion and heel-raise tests.