Plantairflexie

Plantairflexie, or plantar flexion, is an anatomical movement of the ankle that points the toes downward, increasing the distance between the top of the foot and the shin. It occurs primarily at the talocrural joint and is essential for actions such as standing on tiptoe, pushing off during gait, and jumping. It is opposite to dorsiflexion, which brings the toes upward toward the shin.

The movement is produced mainly by the calf muscles, collectively known as the triceps surae (gastrocnemius and soleus). These muscles converge into the Achilles tendon, which inserts into the calcaneus (heel bone). The gastrocnemius is more active when the knee is extended, while the soleus contributes regardless of knee position. Secondary plantarflexors include the tibialis posterior, flexor digitorum longus, flexor hallucis longus, and to a lesser extent the fibularis (peroneus) muscles, providing additional strength and stabilization.

Normal range of plantar flexion is typically around 40 to 50 degrees with the knee extended, though values vary among individuals. Plantar flexion is constrained by neural and musculoskeletal factors, including the integrity of the tibial nerve and the tendons of the posterior leg. The movement plays a key role in propulsion during walking and running and in stabilizing the foot during standing and uneven surfaces.

Clinical relevance includes assessing plantarflexion strength to evaluate posterior chain function, diagnosing Achilles tendon injuries or tendinopathy, and identifying nerve impairment. Limitations or pain during plantar flexion can indicate overuse, tendon pathology, or nerve compromise.