The muscle's fibers run vertically downward, ending in a rounded tendon. This tendon passes behind the medial condyle of the femur, curves around the medial condyle of the tibia where it becomes flattened, and inserts into the upper part of the medial surface of the body of the tibia, below the condyle. As a result of this the muscle is a lower limb adductor. At its insertion the tendon is situated immediately above that of the semitendinosus muscle, and its upper edge is overlapped by the tendon of the sartorius muscle, which it joins to form the pes anserinus. The pes anserinus is separated from the medial collateral ligament of the knee-joint by a bursa.
A few of the fibers of the lower part of the tendon are prolonged into the deep fascia of the leg.
Gracilis muscle is widely used in reconstructive surgery, either as a pedicled flap or as a free microsurgical flap. Both pedicled and free flaps can be muscular or musculocutaneos (the so- called "composite flaps"). As a pedicled flap, gracilis muscle can be used in perineal and vaginal reconstruction, after oncological surgery, in the treatment of recurrent anovaginal and rectovaginal fistulas as well in the coverage of the neurovascular bundle after vascular surgery .
As a functioning pedicled flap the gracilis muscle can be transferred for the treatment of anal incontinence. This technique called graciloplasty was described in the 1950's by Pickrell and was revolutionized in the late 1980's by the introduction of chronic muscle electro-stimulation. The gracilis microsurgical free flap is commonly used in the reconstruction of upper and lower limbs, in breast reconstruction and, as a free functioning flap, to restore forearm function or in dynamic reconstruction of facial paralysis. Gracilis Muscles Clinical Role