Sartorius muscle | |
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![]() Muscles of the right leg, viewed from the front. (Rectus femoris removed to reveal the vastus intermedius.) | |
Details | |
Origin | Anterior superior iliac spine of the pelvic bone |
Insertion | anteromedial surface of the proximal tibia in the pes anserinus |
Artery | femoral artery |
Nerve | femoral nerve (sometimes from the intermediate cutaneous nerve of thigh) |
Actions | Flexion, abduction, and lateral rotation of the hip, extension of the knee [1] |
Identifiers | |
Latin | musculus sartorius |
TA98 | A04.7.02.016 |
TA2 | 2610 |
FMA | 22353 |
Anatomical terms of muscle |
The sartorius muscle ( /sɑːrˈtɔːriəs/ ) is the longest muscle in the human body. [2] It is a long, thin, superficial muscle that runs down the length of the thigh in the anterior compartment. [3]
The sartorius muscle originates from the anterior superior iliac spine, [4] 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. [3] 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. [3]
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. [3]
Like the other muscles in the anterior compartment of the thigh, the sartorius is innervated by the femoral nerve. [3] [4]
It may originate from the outer end of the inguinal ligament, the notch of the ilium, the ilio-pectineal line or the pubis.
The muscle may be split into two parts, and one part may be inserted into the fascia lata, the femur, the ligament of the patella or the tendon of the semitendinosus.
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. [5]
The sartorius muscle can move the hip joint and the knee joint, but all of its actions are weak, making it a synergist muscle. [4] At the hip, it can flex, weakly abduct, and laterally rotate the femur. [4] At the knee, it can flex the leg; when the knee is flexed, sartorius medially rotates the leg. [3] [1] Sitting cross-legged demonstrates all four actions of the sartorius. [3]
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. [6] The pes anserinus involves the tendons of the gracilis, semitendinosus, and sartorius muscles; these tendons attach onto the anteromedial proximal tibia. When inflammation of the bursae underlying the tendons occurs, they separate from the head of the tibia.[ medical citation needed ]
The name sartorius comes from the Latin word sartor, meaning tailor, [7] and it is sometimes called the tailor's muscle. [3] This name was chosen in reference to the cross-legged position in which tailors once sat. [3] In French, a 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 origin 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 crossbody pedaling. This combination of lateral rotation and flexion of the hip and flexion of the knee gave tailors particularly developed sartorius muscles.
The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males.
In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb.
The quadriceps femoris muscle is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large fleshy mass which covers the front and sides of the femur. The name derives from Latin four-headed muscle of the femur.
The pectineus muscle is a flat, quadrangular muscle, situated at the anterior (front) part of the upper and medial (inner) aspect of the thigh. The pectineus muscle is the most anterior adductor of the hip. The muscle does adduct and internally rotate the thigh but its primary function is hip flexion.
In vertebrate anatomy, hip refers to either an anatomical region or a joint.
The biceps femoris is a muscle of the thigh located to the posterior, or back. As its name implies, it has two parts, one of which forms part of the hamstrings muscle group.
In the human body, the adductor longus is a skeletal muscle located in the thigh. One of the adductor muscles of the hip, its main function is to adduct the thigh and it is innervated by the obturator nerve. It forms the medial wall of the femoral triangle.
The adductor magnus is a large triangular muscle, situated on the medial side of the thigh.
The gracilis muscle is the most superficial muscle on the medial side of the thigh. It is thin and flattened, broad above, narrow and tapering below.
The semimembranosus muscle is the most medial of the three hamstring muscles in the thigh. It is so named because it has a flat tendon of origin. It lies posteromedially in the thigh, deep to the semitendinosus muscle. It extends the hip joint and flexes the knee joint.
The semitendinosus is a long superficial muscle in the back of the thigh. It is so named because it has a very long tendon of insertion. It lies posteromedially in the thigh, superficial to the semimembranosus.
The iliopsoas muscle refers to the joined psoas major and the iliacus muscles. The two muscles are separate in the abdomen, but usually merge in the thigh. They are usually given the common name iliopsoas. The iliopsoas muscle joins to the femur at the lesser trochanter. It acts as the strongest flexor of the hip.
The tensor fasciae latae is a muscle of the thigh. Together with the gluteus maximus, it acts on the iliotibial band and is continuous with the iliotibial tract, which attaches to the tibia. The muscle assists in keeping the balance of the pelvis while standing, walking, or running.
The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee.
The fascia lata is the deep fascia of the thigh. It encloses the thigh muscles and forms the outer limit of the fascial compartments of thigh, which are internally separated by the medial intermuscular septum and the lateral intermuscular septum. The fascia lata is thickened at its lateral side where it forms the iliotibial tract, a structure that runs to the tibia and serves as a site of muscle attachment.
Pes anserinus refers to the conjoined tendons of three muscles of the thigh. It inserts onto the anteromedial surface of the proximal tibia. The muscles are the sartorius, gracilis and semitendinosus sometimes referred to as the guy ropes. The name "goose foot" arises from the three-pronged manner in which the conjoined tendon inserts onto the tibia.
The posterior compartment of the thigh is one of the fascial compartments that contains the knee flexors and hip extensors known as the hamstring muscles, as well as vascular and nervous elements, particularly the sciatic nerve.
The anterior compartment of thigh contains muscles which extend the knee and flex the hip.
The knee bursae are the fluid-filled sacs and synovial pockets that surround and sometimes communicate with the knee joint cavity. The bursae are thin-walled, and filled with synovial fluid. They represent the weak point of the joint, but also provide enlargements to the joint space. They can be grouped into either communicating and non-communicating bursae or, after their location – frontal, lateral, or medial.
Pes anserine bursitis is an inflammatory condition of the medial (inner) knee at the anserine bursa, a sub muscular bursa, just below the pes anserinus.
This article incorporates text in the public domain from page 470 of the 20th edition of Gray's Anatomy (1918)
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