Name

Semimembranosus

Pronunciation

(sem-e-mem-bruh-NO-sus)

Origin/Proximal Attachment

Ischial tuberosity

Insertion/Distal Attachment

Posterior medial aspect of medial tibial condyle

fibres join to form most of oblique popliteal ligament (& medial meniscus)

Action/Relevance

Flexes the knee

Extends the hip

Internally rotates the tibia

Pulls medial meniscus posteriorly during flexion

Innervation

Tibial nerve of sciatic bundle (L5, S1, 2)

Notes

Tendon splits into five discreet regions at the level of the knee.

to tubercle on posterior aspect of medial tibia

series of slips to the medial tibia immediately behind the medial collateral

thin fibrous expansion over popliteus

cord like tendon to inferior lip and adjacent groove on the back of the medial tibial condyle (deep to the medial collateral)

strong expansion that blends with the oblique popliteal lig.

Varies considerably in size.