The middle hamstring
Semitendinosus · musculus semitendinosus
An inner hamstring with a long rope-like tendon, often borrowed to rebuild knee ligaments.
What it does
The semitendinosus runs from the sit bone down the back of the thigh to the inside of the shin. It bends the knee, straightens the hip and turns the lower leg inwards. Its lower half is mostly a long, cord-like tendon.
Surprising fact
Surgeons commonly use its tendon, often with the gracilis tendon, to make a new anterior cruciate ligament when one is torn.
Why it matters
Because its tendon makes such good graft material, a sporting knee injury can be repaired using a part of the same leg.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.