- Anatomy:
- origin: upper and lower aspect of ischial tuberosity:
- insertion: posterior surface of medial condyle of the tibia;
- action: flexes and medially rotates the calf at the knee. extends, adducts and medially rotates the thigh at the hip;
- semimembranous is especially important as stabilizing structure around the posterior and posteromedial aspects of the knee;
- reversed origin-insertion action: when the leg is fixed, gives posterior stability to the pelvis and extends the pelvis on the hip;
- nerve supply: sciatic (tibial branch),
L4,
L5,
S1,
S2: (see
innervation);
- synergists:
semitendinosus, biceps,
gastrocnemius,
gracilis,
sartorius;
- 5 distal expansions;
-
oblique popliteal ligament :
- tendinous attachment is to post capsule & post horn of medial meniscus;
- anterior portion passing beneath the
MCL to insert on tibia;
- insertion to
posterior oblique ligament;
- expansion to aponeurosis of
popliteus muscle;
- Semimembranous Tendinitis:
- is predominant in males;
- average age of onset is 32 years;
- inflammation at the insertion site of direct head of semimembranous tendon into the area of the posterior tubercle of the tibia can be detected by
increased activity on a bone scan in that region;
Ray JM, Clancy WG, Lemon RA: Semimembranous tendinitis: An overlooked
cause of medial knee pain.
Am J Sports Med 1988;16:347-351.
The semimembranosus-tibial collateral ligament bursa. Anatomical study and magnetic resonance imaging.
Surgical Repair of Complete Proximal Hamstring Tendon Rupture.
The Anatomy of the Posterior Aspect of the Knee
An Anatomic Study.
