Which action does the sartorius perform?

Which action does the sartorius perform?

• A. Flex the hip
• B. Extend the knee
• C. Abduct the hip
• D. Medially rotate the hip

Answer: (A)

Sartorius mainly flexes the hip. This long, diagonal muscle crosses the front of the thigh from the pelvis to the inner tibia, so its most direct action at the hip joint is to bend the thigh upward toward the torso. It also helps with abduction and external (lateral) rotation of the hip and assists knee bending, but it does not extend the knee (that’s done by the quadriceps) and it does not medially rotate the hip (it tends to rotate the thigh outward when the hip is flexed). So the best match is flex the hip.

Sartorius mainly flexes the hip. This long, diagonal muscle crosses the front of the thigh from the pelvis to the inner tibia, so its most direct action at the hip joint is to bend the thigh upward toward the torso. It also helps with abduction and external (lateral) rotation of the hip and assists knee bending, but it does not extend the knee (that’s done by the quadriceps) and it does not medially rotate the hip (it tends to rotate the thigh outward when the hip is flexed). So the best match is flex the hip.