Lower limb
Semimembranosus
Musculus semimembranosus
- Origin
- Ischial tuberosity
- Insertion
- Posteromedial surface of the medial tibial condyle
- Function
- Extension of the hip, flexion and internal rotation of the knee
- Innervation
- Tibial nerve (L5-S2)
- Movement & chain
- Part of the hamstrings; works together with semitendinosus and biceps femoris in hip extension and decelerates knee extension at the end of the swing phase of gait.
- Palpation
- Medial in the popliteal fossa, broader and deeper than the tendon of semitendinosus, palpable during resisted knee flexion.
- Clinical
- Frequent site of hamstring injuries in sprinters; the proximal tendon can develop tendinopathy with prolonged sitting on a hard surface.
- Segmental innervation
- Tibial nerve, L5-S2.
- In clinical practice
- Relevant in strength testing of knee flexion and hip extension and in assessing hamstring length, for example with the active knee-extension test.
- Region in the model
- Lower limb