The semitendinosus muscle is one of the hamstrings muscles.
Normal function of semitendinosus muscle
The semitendinosus muscle helps to bend the knee and extend the hip, and also has a function to inwardly rotate the knee.
Semitendinosus tendon as a graft material
Because of its long tendon, the semitendinosus can be harvested using a tendon stripper, and then folded into four and used for cruciate ligament reconstruction. It can also be used to stabilise the patella in a tenodesis procedure.