Vastus Medialis Muscle
Semimembranosus – Attachments, Actions & Innervation
Attachments of Semimembranosus: Origin & Insertion
Origin: (proximal attachments)
a.Ischial tuberosity of os coxa.
Insertion: (distal attachments)
a.Posterior medial condyle of tibia.
Actions of Semimembranosus on the leg (tibia & fibula):
a. Flexes leg at knee.
b. Medially rotates leg at knee when knee is flexed.
c. It also extends thigh at hip.
Nerve to Muscle and its Spinal Segment:
a.Tibial (nerve) portion of sciatic nerve (L5, S1, S2).