It arises by a thin
aponeurosis from the anterior margins of the lower half of the
symphysis pubis and the upper half of the
pubic arch. 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. For this reason, 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.
Relations By its inner or superficial surface gracilis is in relation with the
fascia lata, and below with the
sartorius and internal
saphenous nerve; the internal
saphenous vein crosses it lying superficially to the fascia lata. By its outer or deep surface with the
adductor longus,
brevis, and
magnus, and the internal lateral ligament of the knee-joint, from which it is separated by a synovial bursa common to the tendons of the gracilis and
semitendinosus.
Nerve supply The
obturator nerve innervates the gracilis muscle via the lumbar spinal vertebrae. ==Function==