The thigh muscles are divided into three groups. The anterior group is the flexors, the posterior group is the extensors, and the medial group is responsible for adducing the thigh. They have a significant mass and length, act on the hip and knee joints, performing a static and dynamic function when moving or standing. Like the pelvic muscles, muscle fibers of the lower extremities achieve maximum development, which can be associated with upright posture.
Tailor muscle: location
This muscle (musculus sartorius) is the longest among the muscle fibers of the body. In the proximal part, it is attached to the superior iliac spine and obliquely descends along the front surface of the thigh. The peculiarity is that at the same time it is directed from the outside inwards and forms a kind of crypt over the
femoral artery, saphenous nerve and vein in the gunter channel.
In the lower thigh, the tailor muscle runs almost vertically and crosses the medial condyle. In the distal region, it ends with a tendon, attaching to the fascia of the lower leg.
Features of the tailor muscle
This muscle got its name due to participation in the movements of the hip joint, in which a person can acquire the pose of a tailor with legs crossed (the word "sartor" translates as "tailor").
The tendons of musculus sartorius together with the tendons of the thin and semi-tendon muscle fibers form a fibrous triangular plate, which is called the "goose foot".
It is worth noting that the tailor muscle refers to fibers that are capable of significantly changing their length during contraction. The rectus abdominis muscle, as well as the thin and semi-tendon muscle , also have a similar property. A feature of the tailor muscle fibers is that they do not form clear bundles. This leads to the fact that their neuromuscular synapses are characterized by an unusual distribution. In addition, the tailor muscle can be divided into two parallel abdomen or intersected by a tendon constriction, which leads to its separation 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 retracted, as well as in cases when the lower leg is bent. In addition, it is well palpated in the upper thigh.
The role of tailor muscle
Musculus sartorius is involved in flexion and abduction of the thigh, and this muscle is responsible for outward movements, not inwards. With internal rotation of the thigh, it is not involved. When trying to carry out external rotation, it either does not activate at all, or is not fully involved. In a sitting position, the external rotation of the tailor muscle is accompanied by moderate activity. When bending the knee joint, this muscle fiber is activated more actively if bending of the hip joint takes place at the same time.
It should be noted that during the EMG examination it was revealed that the tailor muscle actively works when playing volleyball or basketball. At the same time, musculus sartorius on the left side is more actively involved in any movements with the right hand (for example, while playing tennis), and also works when walking, jumping or riding a bicycle.
So, together with other muscle fibers, the tailor muscle, whose functions include movements of the lower extremities, provides outward rotation of the thigh, and is also responsible for bending the lower leg.
Tailor muscle innervation
The femoral nerve, which consists of 2-4 roots, is responsible for the innervation of musculus sartorius. The branches of this nerve innervate the skin of the inner surface of the thigh and the medial region of the lower leg to the edge of the foot.
With pathological changes in the femoral nerve, paresis or paralysis can develop, as well as a decrease in tone or tendon reflexes. Prolonged muscle paralysis 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, sensitivity disorders in the form of paresthesia, hyposthesia, or complete anesthesia can be observed. Sometimes, on the contrary, a change in sensitivity is recorded as hyperpathy, when patients have burning pains that cannot be relieved by analgesics.
In violation of the innervation of the tailor muscle, walking is usually impaired, which can be explained by the difficulties of flexion of the lower limb in the hip joint or the inability to properly lift the thigh.
What to do if the tailor muscle is damaged?
Femoral neuropathy, which disrupts the contractility of the tailor 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.
If there are signs of damage to the femoral nerve, which is accompanied by impaired flexion of the lower limb, you should consult a neurologist. He will conduct a neurological examination, electrodiagnostics, and if necessary, will prescribe computed tomography, MRI of the retroperitoneal space, as well as appropriate treatment.
When the tailor muscle of the thigh is damaged, drug therapy is effective. The method of relaxation and stretching of affected muscle fibers, femoral nerve blockade and correction of excessive leg extension and changes in the length of the lower limb due to the development of contractures are also used. It is worth noting that a positive result can only be obtained by correcting the work of muscles that are functionally related to the affected area.