Gracilis Muscle Anatomy Overview

The gracilis muscle (L., slender) is a long, strap-like muscle and is the most medial muscle of the thigh. It is the most superficial of the adductor group and the weakest member. It is the only one of the group to cross the knee joint as well as the hip joint.

Gracilis Muscle Anatomy

The gracilis joins with two other two-joint muscles from the other two compartments (the sartorius and semitendinosus muscles). Thus, the three muscles are innervated by three different nerves. They have a common tendinous insertion, the pes anserinus (L., goose’s foot), into the superior part of the medial surface of the tibia.

See Also: Semitendinosus Muscle Anatomy

The gracilis is a synergist in adducting the thigh, flexing the knee, and rotating the leg medially when the knee is flexed. It acts with the other two “pes anserinus” muscles to add stability to the medial aspect of the extended knee, much as the gluteus maximus and tensor fasciae latae do via the iliotibial tract on the lateral side.

The gracilis tendon can be used in reconstructive surgery of the anterior cruciate ligament (ACL) of the knee. The gracilis muscle also has surgical use in patients who have lost the muscular function of their digits, patients with facial palsy, or brachial plexus injuries.

See Also: Thomas Test Interpretation for Hip Flexibility 

When patients have pain along the distal portion of their gracilis tendon, where it becomes the pes anserinus, there should be a high suspicion of pes anserinus bursitis, especially if there is edema present. Pes anserinus bursitis is commonly seen in patients with obesity or osteoarthritis or who are female.

References & More

1. Clinically Oriented Anatomy, 8th Edition.
2. Khan IA, Bordoni B, Varacallo M. Anatomy, Bony Pelvis and Lower Limb: Thigh Gracilis Muscle. [Updated 2023 Apr 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538229/