The Gracilis is a long, strap-like muscle on the medial side of the thigh. Its attachment to the body of the pubis is restricted in size. The muscle tapers as it approaches the knee, first lying between the sartorius and the semimembranosus, then between the sartorius and the semitendinosus. It is a member of the pes anserinus (sartorius, gracilis, semitendinosus) or "goose-foot" tendon. It is the only member of the medial group that crosses the knee joint. The gracilis functions weakly to adduct, flex, and medially rotate the thigh, and to flex and medially rotate the leg. The gracilis muscle is often used as a transplant to replace a damaged muscle in the hand. Once transplanted, it provides good function because of its fusiform composition.

A rather complicated bursa, the anserine bursa, intervenes between the pes anserinus tendons and the tibia. The bursa may become painful and distended as a result of acute or chronic trauma to the medial side of the knee.