The longissimus muscle spans the entire back and belongs to the local back muscles. The skeletal muscle is mainly responsible for the erection of the spine and consists of three different parts. Various maladjustments are associated with the longissimus muscle, especially the lordosis.

What is the longissimus muscle?

The back muscles consist of different parts. In addition to the auxiliary muscles in this context, the autochthonous back muscles should be mentioned. The autochthonous back muscles in turn contain the sacrospinous system, which is composed of the muscles longissimus cervicis, longissimus capitis and longissimus thoracis.

Together, these three muscle parts form the entity of the longissimus muscle. The medical literature sometimes mentions a fourth part of the muscle, the so-called longissimus lumborum. However, other authors interpret this part of the muscle as a part of the iliocostalis muscle. This assignment problem fits in principle with the local back muscles, whose individual entities are difficult to differentiate.

The longissimus muscle is also called the erector spinae muscle, which literally means "erector of the spine." Together with other muscles of the back, it forms the epicenteral musculature, with the innervation of the skeletal muscle segmented by the rami posteriores of the spinal nerves.

Anatomy & Construction

The longissimus muscle extends across the entire human back and extends from the sacrum to the head. The skeletal muscle is located between the iliocostalis and semispinalis muscles, with which it forms together the erector spinae muscle and the epaxial stem musculature.

The longissimus muscle lies with each of its parts on the back of the vertebral transverse processes. The portion of the longissimus thoracis muscle originates from the facies dorsalis at the sacrum. In addition, the spinous processes of the lumbar vertebrae and the transverse processes of the lower thoracic vertebrae are regarded as the region of origin. The part of the musculus longissimus cervicis, on the other hand, originates from the transverse processes of the first to sixth thoracic vertebrae.

Again, the transverse processes of the third cervical vertebra up to those of the third thoracic vertebra are the origin of the longissimus capitis muscle. Thus, the longissimus thoracis muscle attaches to the transverse processes of the thoracic spine and lumbar spine. On the lumbar spine, the second to twelfth ribs between Angulus costae and Tuberculum costae are used as an approach. For the longissimus cervicis muscle, the posterior tuberculosis on the second to seventh cervical vertebrae is considered. For the musculus longissimus capitis it is the processus mastoideus.

Function & Tasks

The longissimus muscle performs different functions in the human body. All of these are motor functions that focus more or less on the area of ​​the back. Like any muscle, the longissimus muscle is understood to be a neuromuscular unit of muscle tissue and the supplying nerve structures. Ultimately, therefore, it is not possible to speak directly about the functions of the longissmus muscle.

The functions of the neuromuscular entity of the musculus longissimus and rami posteriores should be more correctly stated.As the muscle consists of three different parts, its motor functions can be threefold.The muscular part of the longissimus thoracis muscle is responsible for extension and lateral tilting in the thoracic and lumbar spine. This also includes the extension and dorsiflexion of the thoracic and lumbar spine, which also promotes expiration through the muscle part The longissimus cervicis muscle has similar functions, and its contraction causes dorsiflexion and sideways tilting in the cervical and thoracic spine.

The contraction of the longissimus capitis muscle in turn triggers dorsiflexion, rotation and lateral tilt of the head and cervical spine. In principle, the bilateral contraction of the longissimus muscle causes an erection or extension of the spinal column with elevation of the neck. The one-sided contraction, however, is responsible for the lateral inclination of the spine. The contraction commands are given to the muscle from the central nervous system.

On efferent pathways, central nervous system commands in the form of action potentials reach the motor endplate where they are transmitted to the muscle. The sometimes most important symptom of a lordosis is the so-called curvature belly, which in this case points in the ventral direction.

Diseases

The individual parts of the longissimus muscle, like all other parts of the muscle, can be affected by tension, inappropriate stress, cramps, inflammation and other muscle diseases. In addition, lesions on the supplying nerves as well as central lesions in the area of ​​the spinal cord can cause paralysis of the muscle or its parts.

Trauma, tumors, compression or inflammation may be responsible for such paralyzes. Also diseases of the peripheral or central nervous system can in principle cause a paralysis of the muscle. Far more frequently than paralyzes, however, the longissimus muscle is associated with pathological phenomena such as lordosis and scoliosis. The lordosis corresponds to a curvature of the spine forward. In scoliosis there is a lateral deviation of the spine. These maladjustments may be due to individual states of the longissimus muscle.

The trigger for a hollow spine in the sense of a lordosis can, for example, be a back muscle that is poorly trained due to lack of exercise and therefore hypertonic, which no longer relaxes properly. Especially in later stages, a lordosis leads to more or less severe back pain and may also promote sequelae such as a herniated disc or the phenomenon of sliding vertebrae. For this reason, it is important to prevent the lordosis. In addition to back exercises, detonation techniques, relaxation techniques and balanced training of the back and abdominal muscles are considered preventive measures.

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