MuscleThigh — posterior (hamstrings)
Semitendinosus
Latin: M. semitendinosus sinistra
Location: Thigh
Paired structure: one on the left and one on the right side of the body.
View the semitendinosus in 3DOrigin
Ischial tuberosity (common tendon with biceps femoris long head).
Insertion
Medial surface of the superior tibia (pes anserinus, with gracilis and sartorius).
Action
Extends the hip, flexes the knee and medially rotates the flexed knee; the long distal tendon crosses to the inner leg.
Nerve supply
Tibial division of the sciatic nerve (L5–S2).
Blood supply
Perforating branches of the profunda femoris.
Clinical relevance
The semitendinosus tendon is the standard graft harvested for ACL reconstruction — its loss barely affects daily function. Pes anserinus bursitis aches over its insertion.
Educational anatomy reference, not medical advice. About this content.