Sartorius muscle

Last revised by Roney Sam on 20 Dec 2021

The sartorius muscle is the long obliquely oriented muscle of the anterior compartment of the thigh. It is the longest muscle in the human body 3.

  • origin: immediately below the anterior superior iliac spine
  • insertion: as part of the pes anserinus tendon (anteromedial surface of the tibia, just distal to the tibial tuberosity)
  • action
    • primary: flexion of the hip and knee
    • secondary: lateral rotation and weak abduction of the thigh (such as when sitting cross-legged)
  • innervation: individual muscular branch from anterior division of the femoral nerve (L2, L3, L4)
  • blood supply:
    • proximal third: branches from the femoral artery, profunda femoris, quadriceps artery, lateral circumflex femoral artery
    • middle third: branches of femoral artery 
    • distal third: branches of femoral artery, descending genicular arteries

The sartorius muscle has long parallel fibers that extend for the whole length of the muscle, running obliquely from lateral to medial down the thigh anterior to the quadriceps, in the same direction as the inguinal ligament and the fibers of the external oblique muscles. It spirals obliquely down across the thigh, passes downwards on the fascial roof of the adductor canal, lies near the posterior aspect of the medial condyle of the femur, and its tendon inserts onto the anteromedial aspect of the tibia as part of the pes anserinus tendon.

The medial border of the sartorius is the lateral boundary of the femoral triangle. It forms the anterior boundary of the adductor canal.


Near origin 

  • pierced by the intermediate cutaneous nerve of thigh

Near insertion

  • posterior
  • deep
    • bursae separating it from the gracilis and semitendinosus tendons
  • pierced by the infrapatellar branch of saphenous nerve above the insertion of the sartorius

Flexion, abduction and lateral rotation of the hip, and flexion of the knee - the movements involved in drawing the lower limb into the cross-legged sitting position. None of these actions are strong in isolation - most of its action is synergistic.

May originate from the outer end of the inguinal ligament, the iliac notch, the iliopectineal line or the pubis.

The muscle may split into two parts, one of which may be inserted onto the fascia lata, the femur, the patellar ligament, or the tendon of semitendinosus.

Named after tailors (sartor is Latin for tailor or patcher), who would often sit cross-legged when working 3.

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Cases and figures

  • Figure 1: femoral triangle (diagram)
    Drag here to reorder.
  • Case 1: labeled 73
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