The plantaris (also plantaris muscle, latin: musculus plantaris) is a superficial muscle of the posterior group of the lower leg muscles. The plantaris consists of a belly and a long thin tendon.
The plantaris originates from the lateral condyle of the femur.
The plantaris passes inferomedially and inserts into the Achilles tendon.
The plantaris plays role in flexion of the knee and foot.
The plantaris is innervated by the tibial nerve that arises from the sciatic nerve of the sacral plexus.