Lower limb

Pes anserinus (goose foot tendon complex)

Tendo communis pes anserinus

Origin

Combined terminal tendons of sartorius, gracilis and semitendinosus

Insertion

Anteromedial side of the tibia, distal to the medial joint line of the knee

Function

Flexion of the knee and internal rotation of the lower leg with the knee bent; important dynamic stabilizer of the medial knee against valgus loading

Innervation

Mixed: femoral nerve (sartorius), obturator nerve (gracilis) and tibial nerve (semitendinosus)

Movement & chain

Functions as a dynamic stabilizer (the 'fourth cruciate ligament') that protects the knee against valgus and external rotation forces via three muscles during walking and stair climbing.

Palpation

Palpable as a broad tendinous band on the anteromedial side of the proximal tibia, approximately 5 cm below the joint line.

Clinical

Common site of pes anserinus bursitis, especially in runners and people with knee osteoarthritis, causing tenderness just below the medial joint line.

Segmental innervation

L2–L4 (femoral, obturator) & L5–S2 (tibial)

In clinical practice

Commonly used injection site (corticosteroid) for pes anserinus bursitis, just below the medial joint line of the knee.

Region in the model

Lower limb