Semitendinosus muscle
| Semitendinosus muscle | |
|---|---|
| Muscles of the gluteal and posterior femoral regions. Semitendinosus labeled at bottom left. | |
| Horizontal section of left thigh, viewed from above.  Semitendinosus visible at bottom right. | |
| Details | |
| Origin | Lower quadrangular part of tuberosity of the ischium | 
| Insertion | Pes anserinus (tibia) | 
| Artery | Inferior gluteal artery, perforating arteries | 
| Nerve | Sciatic (tibial, L5, S1, S2) | 
| Actions | Flexion of knee, extension of the hip joint | 
| Antagonist | Quadriceps muscle | 
| Identifiers | |
| Latin | musculus semitendinosus | 
| TA98 | A04.7.02.035 | 
| TA2 | 2641 | 
| FMA | 22357 | 
| Anatomical terms of muscle | |
The semitendinosus (/ˌsɛmiˌtɛndɪˈnoʊsəs/) is a long superficial muscle in the back of the thigh. It is so named because it has a very long tendon of insertion. It lies posteromedially in the thigh, superficial to the semimembranosus.