Tailor muscle: its placement, functions, innervation

Muscles of the hip are divided into three groups. The anterior group is the flexor, the posterior is the extensor, and the medial is responsible for bringing the hip. They have a significant mass and length, act on the hip and knee joint, performing a static and dynamic function when moving or standing. Like the pelvic muscles, the muscle fibers of the lower limbs reach their maximum development, which can be related to the upright.

Tartal muscle: location

This muscle (musculus sartorius) is the longest muscle fiber of the body. In the proximal part, it is attached to the superior iliac spine and down the front surface of the thigh. The peculiarity is that while it is directed from the outside into the interior and forms a kind of crypt above the femoral artery, subcutaneous nerve and vein in the canal channel.

In the lower part of the thigh, the sartorius muscle runs almost vertically and crosses the medial condyle. In the distal region, it ends with a tendon, attaching to the fascia of the shin.

Peculiarities of sartorius muscle

This muscle got its name due to participation in hip joint movements , in which a person can acquire a tailor's pose with crossed legs (the word "sartor" translates as "tailor").

Musculus sartorius tendons, together with the tendons of the thin and semitendinous muscle fibers form a fibrous triangular plate, which is called the "goose paw".

It should be noted that the sartorius muscle refers to fibers that are capable of significantly changing their length when cutting. A direct muscle of the abdomen, as well as a thin and semitendinous muscle , also has a similar property. The peculiarity of the fibers of the sartorius muscle is that they do not form distinct beams. This leads to the fact that their neuromuscular synapses are characterized by an unusual distribution. In addition, the sartorius muscle can be divided into two parallel abdomen or intersect with a tendon constriction, which leads to its division into the upper and lower parts.

It should also be mentioned that this muscle is clearly visible under the skin, if the hip is bent or removed, as well as in cases when the shin is unbent. In addition, it is well palpable in the upper region of the thigh.

Role of sartorius muscle

Musculus sartorius participates in flexion and hip abduction, and this muscle is responsible for movements outward, not inward. With internal rotation of the thigh, it is not involved. When trying to implement an external rotation, it is either not activated at all, or is not fully utilized. In the sitting position, external rotation of the sartorius muscle is accompanied by moderate activity. When bending the knee joint, this muscle fiber is activated more actively if the hip joint is flexed simultaneously.

It should be noted that the EMG survey revealed that the sartorius muscle is active when playing volleyball or basketball. In this case, the musculus sartorius on the left side is activated more actively with any movements by the right hand (for example, during a game of tennis), and also works when walking, jumping or riding a bicycle.

So, along with other muscle fibers, the sartorius muscle, whose functions involve the movement of the lower limbs, ensures the hip turns outward, and is also responsible for flexion of the shin.

Innervation of sartorius muscle

The innervation of the musculus sartorius corresponds to the femoral nerve, which consists of 2-4 roots. The branches of this nerve innervate the skin of the inner surface of the thigh and the medial region of the shin to the edge of the foot.

With pathological changes of the femoral nerve, paresis or paralysis can develop, and also tone or tendon reflexes may decrease. Prolonged paralysis of muscles leads to their atrophy and to the appearance of contractures, which are accompanied by pathological placement of the limb through the activation of healthy antagonist muscles.

In addition, there may be impaired sensitivity in the form of paresthesia, hyposthenia, or complete anesthesia. Sometimes, on the contrary, a sensitivity change is recorded according to the type of hyperpathy, when patients have burning pains that are not removed by analgesics.

If the innervation of the sartorius muscle is disturbed, walking is usually disturbed, which can be explained by the difficulty of flexing the lower limb in the hip joint or the inability of a normal hip lift.

What to do if the sartorius muscle is damaged?

Neuropathy of the femoral nerve, which violates the contractility of the sartorius muscle, most often develops after surgical interventions in the pelvic organs or thigh. The cause may also be stretching or direct compression of muscle fibers. It is also worth mentioning that neuropathy can occur against the background of diabetes mellitus.

If there are signs of damage to the femoral nerve, which is accompanied by violations of flexion of the lower limb, you should consult a neurologist. He will conduct a neurologic examination, electrodiagnostics, if necessary, prescribe a computer tomography, retroperitoneal MRI, and appropriate treatment.

When the sartorius muscle of the thigh is damaged, drug therapy is effective. Also, the method of relaxation and stretching of affected muscle fibers, blockage of the femoral nerve and correction of excessive extension of the leg and changes in the length of the lower limb due to the development of contractures are also used. It is worth noting that you can get a positive result only with the correction of the muscles, which are functionally related to the affected area.