Gracilis
Musculus gracilis
A long, slender strap muscle on the medial side of the thigh, the most superficial adductor. It adducts the thigh and flexes and medially rotates the knee.
Overview
Gracilis ("slender") arises from the body and inferior ramus of the pubis and descends along the medial thigh. Its tendon passes behind the medial femoral condyle and inserts on the upper medial surface of the tibia in the pes anserinus, between sartorius (in front) and semitendinosus (behind). It is the only adductor that crosses the knee. It adducts the thigh, flexes the knee and medially rotates the flexed leg. It is supplied by the anterior division of the obturator nerve.
Because it is expendable (other adductors compensate) and has a reliable proximal vascular pedicle from the medial circumflex femoral or profunda femoris artery, it is widely used as a free or pedicled flap and its tendon as a graft (e.g. in ACL reconstruction with semitendinosus).
Anatomy
- Origin
Body and inferior ramus of the pubis.
- Insertion
Superior part of the medial surface of the tibia (pes anserinus).
- Action
Adduction of the thigh; flexion and medial rotation of the leg at the knee.
- Innervation
Obturator nerve (anterior division).
- Nerve roots
L2–L3
- Arterial supply
Medial circumflex femoral artery and branches of the profunda femoris (main pedicle); descending genicular branches distally.
- Relations
The most medial and superficial muscle of the thigh. Contributes to the pes anserinus with sartorius and semitendinosus.
Function
- Adducts the thigh
- Flexes the knee and medially rotates the leg
Clinical significance
Gracilis flap and graft
Used for muscle transfer (facial reanimation, anal sphincter reconstruction), for covering defects and as a hamstring graft for ACL reconstruction.
Mnemonics
Pes anserinus
"Say Grace before Tea": Sartorius, Gracilis, semiTendinosus, in order from anterior to posterior.
Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.