AnatoMemory

Muscle

Semitendinosus

Medial hamstring, long tendon

Lower limbMuscular system

High-yield

Long tendon of the pes anserinus; flexes the knee and medially rotates the flexed leg. Tibial division.

Overview

A medial hamstring with a long cord-like distal tendon, inserting at the pes anserinus and often harvested for ACL grafts.

Reference facts

Origin
Ischial tuberosity
Insertion
Superomedial surface of the tibia (pes anserinus)
Action
Flexes the knee, medially rotates the flexed leg, and extends the hip
Innervation
Tibial division of the sciatic nerve (L5, S1, S2)
Blood supply
Perforating branches of the deep femoral artery

Frequently asked questions

What does the semitendinosus do?

The semitendinosus flexes the knee, medially rotates the flexed leg, and extends the hip.

What nerve innervates the semitendinosus?

The semitendinosus is innervated by the tibial division of the sciatic nerve (L5, S1, S2).

Where does the semitendinosus attach?

The semitendinosus originates from the ischial tuberosity and inserts on the superomedial surface of the tibia (pes anserinus).

What is the blood supply of the semitendinosus?

The semitendinosus is supplied by the perforating branches of the deep femoral artery.