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Muscle guide · Thighs

Sartorius

Also called tailor's muscle

The sartorius is a long, thin strap that runs diagonally across the front of the thigh, from the bony point at the front of the hip to the inside of the shin just below the knee. It is the most superficial muscle at the front of the thigh and often called the longest muscle in the body.

Because it crosses two joints, its actions combine into one familiar position: sitting cross-legged, the way tailors once sat to work, which gave it its name.

5 exercises2 stretches7 with 3D demos2 sourcesUpdated 17 October 2026

Where the sartorius is and what it does

Shaded: the quads area. It marks the region, not the exact outline of the sartorius.
Starts at (origin)
The bony point at the front of the hip.Anterior superior iliac spine
Attaches to (insertion)
The inside of the shin just below the knee, beside the gracilis and semitendinosus tendons.Superomedial tibia at the pes anserinus
What it does
  • Bends the hip and turns the thigh outward.Hip flexion and external rotation
  • Bends the knee and turns the shin inward.Knee flexion and internal rotation
Nerve supply
Femoral nerve (L2, L3, L4).

Source 1

Exercises for the sartorius

No study has measured which exercises work it hardest. These use its actions: lifting the knee, and bending the knee.

Standing band hip flexion demonstrated on the 3D figure3D demoStanding band hip flexionBeginner · A band + An anchor pointStanding march demonstrated on the 3D figure3D demoStanding marchBeginner · No equipmentHanging knee raise demonstrated on the 3D figure3D demoHanging knee raiseIntermediate · Pull-up barSeated Leg Curl demonstrated on the 3D figure3D demoSeated Leg CurlBeginner · Strength machineMachine leg curl demonstrated on the 3D figure3D demoMachine leg curlBeginner · Strength machine

Stretches for the sartorius

Taking the hip behind you, slightly turned in, reverses its hip actions.

Half-kneeling hip flexor stretch demonstrated on the 3D figure3D demoHalf-kneeling hip flexor stretchBeginner · No equipmentCouch stretch demonstrated on the 3D figure3D demoCouch stretchIntermediate · A wall

Problems linked to the sartorius

Pulled-off bone at the front of the hip (teenage athletes)

Until about age 21 to 25 the bony point at the front of the hip is still fusing. A sudden hard contraction of the sartorius, as in sprinting or swinging a bat, can pull a piece of it away. Most heal without surgery.

Source 1

Pain on the inner knee

Overuse where its tendon joins the gracilis and semitendinosus below the knee can inflame the bursa there and cause pain on the inside of the knee.

Sources 1, 2

Questions people ask

What does the sartorius do?

It bends and turns out the hip and bends the knee, which together put the leg in a cross-legged position.

Is the sartorius the longest muscle in the body?

It is generally described that way: it runs from the front of the hip all the way to the inside of the shin below the knee.

Which nerve supplies the sartorius?

The femoral nerve, from the L2 to L4 nerve roots.

Muscles it works with

Sources

  1. StatPearls · Anatomy, Bony Pelvis and Lower Limb: Thigh Sartorius Muscle (2023)
  2. StatPearls · Anatomy, Bony Pelvis and Lower Limb: Thigh Gracilis Muscle (2023)

Anatomy and movement education, not a diagnosis or treatment plan. If you have pain that follows an injury, is severe or getting worse, or comes with numbness, weakness or swelling, get it assessed. Health disclaimer.