Half tendon muscle (M. semitendinosus)

Synonyms

Latin: Semitendinosus muscle
English: semitendinosus muscle

Synergists:
In the hip joint:
Straightener: Gluteus greater and middle muscles (Mm. Glutei maximus et medius), Biceps thigh muscle (M. biceps femoris), Semi-membranous muscle (M. semimembranosus)
Adductors: Comb muscle (M. pectineus), short and long adductor (M. adductor brevis et longus), great adductor (M. adductor magnus), lean muscle (M. gracilis)

In the knee joint:
Flexor: Tailor's Muscle (M. sartorius), lean muscle (M. gracilis), Biceps thigh muscle (M. biceps femoris), Two-headed lower leg muscle (M. gastrocnemicus)

Antagonists:
In the hip joint:
Flexor: Iliac-lumbar muscle (M. iliopsoas), Tailor muscle (M. sartorius), Thigh tie tensioner (M. tensor fasciae latae), Four-headed hamstring muscle - straight part (M. rectus femoris)
Abductors: Thigh Tie Tensioner (M. tensor fasciae latae)glutes, small and medium muscles (M. gluteus minimus et medius)

In the knee joint:
Straightener: Four-headed hamstring muscle (M. quadriceps femoris)

definition

The half-tendon muscle is a muscle of the back of the thigh muscles (the so-called hamstring muscles) and extends roughly from the lower edge of the pelvis to just below the inside of the knee joint, where it attaches to the upper inner shin. When the muscle contracts, it mainly bends the lower leg towards the thigh, but can also help stretch the leg when the leg is raised towards the chest.
The hemisphere muscle bears its unusual name because the tendon with which it attaches to the shin is particularly long. It extends well into the thigh and takes up a large part of the muscle's length, which is why the muscle is literally half muscle and half tendon.
Its insertion tendon is also part of a famous anatomical structure: together with the tendons of the tailor's muscle (M. sartorius) and the slender muscle (M. gracilis) on the upper inner tibia, it forms a fan-shaped, three-part structure that looks like a goose foot and therefore also anatomically so called ("Pes anserinus").

course

Approach: Upper inner shin, so-called "superficial goosefoot" (Pes anserinus superficialis)

Origin: Cusp of the ischium, part of the pelvis (Sciatic tuberosity)

Innervation: Tibial nerve (segment L5-S2)

function

Because of its course, the muscle supports movement in both the hip joint and the knee joint. in the hip joint does he have the function of a Streckers (Extensor) and Adductor. An extension of the hip joint occurs, for example, when extending the bent thigh but also when standing upright. Adduction is the Latin word for Bring up, the hemi-tendon muscle can bring the splayed leg back up to the body.
in the Knee joint the muscle supports the diffraction (Inflection) and the Inward rotation (Internal rotation). In other words, movements in which the lower leg is moved towards the thigh, such as when standing on one leg, or the lower leg is turned inward.

common illnesses

The hemi-tendon muscle can be damaged from damage to the Sciatic nerve ("Sciatic nerve") may be affected. The nerve supplying it (N. tibialis) arises from the sciatic nerve. If there is serious damage, the entire ischiocrual musculature on the back of the thigh can fail. Thus, the front thigh muscles of the opponent are missing and painful hyperextension of the knee joint can occur Quadriceps femoris muscle come.
In addition, athletes can experience typical muscle injuries such as overstrain strain, Torn hamstring or more complete Muscle tear come. (Tendon) irritations can also occur.
The muscle is not a disease but has an important clinical role in the treatment of a disease front Torn cruciate ligament. In so-called "cruciate ligament plasty", the most commonly performed cruciate ligament surgery, the tendon of the hemi-tendon muscle is completely removed (rarely also the other muscles). It is then "folded" several times and used as a stable replacement for the cruciate ligament in the knee.

Strengthening and stretching

In principle, all exercises in which the extension of the leg is intensified and the extensor group on the back of the thigh is stretched are suitable for stretching the hemi-tendon muscle. Classically, the athlete achieves this by trying to reach the toes with his fingertips with his legs straight and the back as straight as possible. This stretching exercise is often found to be very uncomfortable and should not be overdone!
The muscles can be strengthened, especially in the gym, on specially designed equipment. All exercises in which the knee joint is bent (if necessary with a counterweight) strengthens the hemisphere muscle. (So-called "leg biceps curls")