The Musculus semimembranosus (lat. for „half membranous muscle“) is one of the back skeletal muscles of the thighs. The name stems from it's broad origin tendon. The tendon as well as the muscle belly show a dent in the upper part in which the Musculus semitendinosus runs through.


M. Semimembranosus - half membranous muscle


  • Sitting bones (Tuber ischiadicum)


  • Condylus medialis der Tibia at the so called Pes anserinus profundus (Condylus medialis tibiae, Lig. popliteum obliquum, Fascia of the M. popliteus): As well as on the inside of the shin bone, on the very top of the knee joint.


  • Hip joint: Extension, Adduktion (pull towards), slight outward rotation of the thigh
  • Knee joint: Extention of the knee joint, inside rotation of the kalf


  • Nervus Tibialis

Spinal Segments

  • L5-S1: A herniated disc in this area would impair this muscle.