The longest muscle in the human body, the sartorius is a long thin muscle which runs from the top of the lower leg all the way up to the hip. Its name is Latin, meaning “to do tailoring”, reflecting the way tailors would sit crossed legged.
The muscle is active during movements of both the knee and the hip. It is recruited during knee flexion, and is therefore targeted during leg curling exercises. The muscle is also a hip flexor, engaged during leg raises and athletic movements involving the knees being brought upward (jumping, sprinting etc).