Anatomy Of The Semimembranosus Muscle

Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA
Anatomy of Semimembranosus

One of the 3 muscles that make up the hamstring. The other 2 are , semitendinosus and biceps femoris

Origin

• Upper lateral part of ischial tuberosity

Insertion

• Back of the posterior surface of the medial tibial condyle

Nerve supply

• Sciatic nerve

Action
1.Flexion of knee
2.Extension of hip
3.Medial rotation of tibia

Conditions associated

1. Bakers cyst

• Cyst located between semimembranosus and medial gastrocnemius muscles
• Commonly caused by knee arthritis or a meniscal tear
• It is connected to the knee joint through a valvular opening
• Knee effusion from intraarticular pathology allows the fluid to go through the valve into the cyst in one direction

2.Approach to posteromedial fracture of tibial plateau

• Through an incision between semimembranosus and medial gastrocnemius