The popliteus (Latin: musculus popliteus) is a small triangular-shaped deep muscle located in the posterior compartment of the lower leg behind the knee joint. It forms the floor of the popliteal fossa. Together with the tibialis posterior, flexor digitorum longus and flexor hallucis longus muscles, the popliteus is known as one of the deep posterior leg muscles. It is the smallest and most superficial muscle of the group, and it stretches over the knee joint from the femur to the tibia.

OriginLateral condyle of femur, posterior horn of lateral meniscus
InsertionPosterior surface of tibia superior to soleal line
ActionUnlocks knee joint, knee joint stabilization, flexion of knee, internal rotation of tibia
InnervationTibial nerve (L4 - S1)
Blood supply Medial inferior genicular artery, branches of posterior tibial artery


The popliteus muscle originates from the lateral condyle of the femur and posterior horn of the lateral meniscus.


The popliteus inserts on the posterior surface of the tibia above the soleal line.


The popliteus muscle unlocks the knee joint - it laterally rotates the femur on the fixed tibia during the gait. Also, it stabilizes the knee joint, provides flexion of the knee and internal rotation of the tibia at the knee joint.


The popliteus is innervated by the tibial nerve (L4 - S1) - a branch of the sciatic nerve.

Blood supply

The popliteus muscle receives arterial blood supply from the medial inferior genicular artery of the popliteal artery. Also, it is supplied by the branches of the posterior tibial artery.