|Origin||Anterior superior iliac spine of the pelvic bone|
|Insertion||anteromedial surface of the proximal tibia in the pes anserinus|
|Nerve||femoral nerve (sometimes from the intermediate cutaneous nerve of thigh)|
|Actions||Flexion, abduction, and lateral rotation of the hip, flexion of the knee|
|Anatomical terms of muscle|
The sartorius muscle originates from the anterior superior iliac spine and part of the notch between the anterior superior iliac spine and anterior inferior iliac spine. It runs obliquely across the upper and anterior part of the thigh in an inferomedial direction. It passes behind the medial condyle of the femur to end in a tendon. This tendon curves anteriorly to join the tendons of the gracilis and semitendinosus muscles in the pes anserinus, where it inserts into the superomedial surface of the tibia.
Its upper portion forms the lateral border of the femoral triangle, and the point where it crosses adductor longus marks the apex of the triangle. Deep to sartorius and its fascia is the adductor canal, through which the saphenous nerve, femoral artery and vein, and nerve to vastus medialis pass.
The tendon of insertion may end in the fascia lata, the capsule of the knee-joint, or the fascia of the leg.
The muscle may be absent in some people.
The sartorius muscle can move the hip joint and the knee joint, but all of its actions are weak, making it a synergist muscle. At the hip, it can flex, weakly abduct, and laterally rotate the thigh. At the knee, it can flex the leg; when the knee is flexed, sartorius medially rotates the leg. Turning the foot to look at the sole or sitting cross-legged demonstrates all four actions of the sartorius.
One of the many conditions that can disrupt the use of the sartorius is pes anserine bursitis, an inflammatory condition of the medial portion of the knee. This condition usually occurs in athletes from overuse and is characterized by pain, swelling and tenderness. The pes anserinus is made up from the tendons of the gracilis, semitendinosus, and sartorius muscles; these tendons attach onto the anteromedial proximal tibia. When inflammation of the bursa underlying the tendons occurs they separate from the head of the tibia.
This name was chosen in reference to the cross-legged position in which tailors once sat. In French, the muscle name itself "couturier" comes from this specific position which is referred to as "sitting as a tailor" (in French : "s'asseoir en tailleur").
There are other hypotheses as to the genesis of the name. One is that it refers to the location of the inferior portion of the muscle being the "inseam" or area of the inner thigh that tailors commonly measure when fitting trousers. Another is that the muscle closely resembles a tailor's ribbon. Additionally, antique sewing machines required continuous cross body pedaling. This combination of lateral rotation and flexion of the hip and flexion of the knee gave tailors particularly enlarged sartorius muscles.
The sartorius is also called the honeymoon muscle.
- Moore, Keith; Anne Agur (2007). Essential Clinical Anatomy. Lippincott Williams & Wilkins. p. 334. ISBN 0-7817-6274-X.
- Moore, Keith L.; Dalley, Arthur F.; Agur, A. M. R. (2013-02-13). Clinically Oriented Anatomy. Lippincott Williams & Wilkins. pp. 545–546. ISBN 9781451119459.
- Scott-Conner, Carol E. H.; David L. Dawson (2003). Operative Anatomy. Lippincott Williams & Wilkins. p. 606. ISBN 0-7817-3529-7.
- Mosby's Medical, Nursing & Allied Health Dictionary, Fourth Edition, Mosby-Year Book Inc., 1994, p. 1394