Lower limb

Semimembranosus Tendon

Tendo musculi semimembranosi

Origin

Continuation of the muscle belly of semimembranosus, which originates from the ischial tuberosity

Insertion

Mainly the posteromedial tibial condyle, with extensions to the oblique popliteal ligament and the popliteal fascia

Function

Transmits the pulling force of semimembranosus to the tibia; stabilizes the medial and posteromedial knee

Innervation

Tibial nerve, branch of the sciatic nerve (L5-S2)

Movement & chain

The tendon fans out distally into several bundles ('pes anserinus profundus'), which gives the medial knee extra stability during flexion and against external rotation.

Palpation

Palpable as a firm cord at the posteromedial side of the popliteal fossa during active knee flexion.

Clinical

Can become chronically irritated with overuse (semimembranosus tendinopathy), sometimes confused with medial meniscus complaints.

Segmental innervation

Tibial nerve, L5-S2.

In clinical practice

Relevant landmark in ultrasound examination of the posteromedial knee, among other things to distinguish tendon irritation from a Baker's cyst.

Region in the model

Lower limb