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Muscles of the back
Last reviewed: 23.04.2024
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Muscles of the back (musculi dorsi) are paired, occupying the entire dorsal side of the trunk, starting from the region of the sacrum and the adjacent parts of the iliac crests to the base of the skull. Being located layer by layer, these muscles have complex anatomical and topographical relations, due to the peculiarities of their development and function. There are superficial and deep muscles of the back. Muscles are covered with fascia, which separate one group of muscles from the other.
Most of the superficial muscles of the back develop in connection with the upper limb. These include the trapezius muscle, the broadest muscle of the back, the muscle that lifts the scapula, the large and small diamond-shaped muscles. The upper and lower posterior jugular muscles are located deeper and attached to the ribs.
Deep muscles that make up the bulk of the back musculature are derived from myotomes - the muscle rudiments of the primary body segments - somites. These muscles include the belt muscles of the head and neck, the muscle, straightening trunk, nasal and other.
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Superficial muscles of the back
The superficial muscles of the back are attached to the bones of the shoulder girdle and humerus and are arranged in two layers. The first layer is formed by a trapezius muscle and the widest muscle of the back, the second one - large and small diamond-shaped muscles, a muscle that lifts the scapula, upper and lower jagged muscles.
The trapezius muscle (M. Trapezius) is flat, triangular in shape, with a wide base facing the posterior middle line. The muscle occupies the upper back and the back region of the neck.
The widest muscle of the back (m. Latissimus dorsi) is flat, triangular in shape, occupying the lower half of the back on the corresponding side. The widest muscle of the back lies superficially, with the exception of the upper edge, which is hidden beneath the lower part of the trapezius muscle. Below the lateral edge of the latissimus muscle of the back forms the medial side of the lumbar triangle (the lateral side of this triangle forms the edge of the outer oblique abdominal muscle, the lower one is the ileum crest).
The muscle lifting the scapula (m. Levator scapulae) begins with tendon bundles on the posterior tubercles of the transverse processes of the upper three or four cervical vertebrae (between the attachment of the middle staircase in the front and the neck muscle in the back). Going down, the muscle is attached to the medial edge of the scapula, between its upper corner and the awn.
Small and large rhomboid muscles (mm. Rhomboidei minor et major) often coalesce and form one muscle. A small rhomboid muscle begins on the lower part of the nuchal ligament, the spinous processes of the VII cervical and 1st thoracic vertebrae and on the bony bundle.
Small and large diamond-shaped muscles
To the ribs are attached two thin flat muscles - upper and lower posterior jagged.
Upper and lower posterior jagged muscles
Deep back muscles
Deep back muscles form three layers: superficial, medium and deep. The superficial layer is represented by the belt muscle of the head, the neck muscle of the neck and the muscle that straightens the spine. The middle layer forms a transverse-awn muscle. The deep layer is formed by inter-osseous, interdissal and suboccipital muscles.
The muscles of the surface layer reach the greatest development, referring to the type of strong muscles that perform predominantly static work. They extend all over the back and back of the neck from the sacrum to the occipital bone. Places of beginning and attachment of these muscles occupy vast surfaces. Therefore, with its contraction, the muscles of the surface layer develop a greater force, holding the vertebral column in the vertical position, which serves as a support for the head, ribs, internals, and upper limbs. Muscles of the middle layer are arranged obliquely, they are thrown from the transverse to the spinous processes of the vertebrae. They form several layers, and in the deepest layer the muscle bundles are the shortest and attach to adjacent vertebrae. The more superficial the muscle bundles lie, the longer they are and through more of the vertebrae they are thrown (from 5 to 6). In the deepest, third, layer, short muscles are not located at all levels of the spine. These muscles are well developed in the most mobile parts of the spinal column: cervical, lumbar and lower thoracic. The third layer also includes muscles acting on the atlanto-occipital joint. These muscles are called the suboccipital muscles (mm. Suboccipitals).
Deep back muscles become visible after the superficial muscles have been laminated and intersected: the broadest muscle of the back, the trapezius muscle, and the rhomboid and jagged muscles.
The belt muscle of the head (m. Splenitis capitis) lies anterior to the upper part of the sternum-mastoid and trapezius muscles. It begins on the lower half of the ligamentous ligament (below the level of the IV cervical vertebra), on the spinous processes of the 7th cervical and the upper three to four thoracic vertebrae. The tufts of this muscle go upwards and laterally and attach to the mastoid process of the temporal bone and to the site under the lateral part of the superior occipital line of the occipital bone.
The neck muscle of the neck (m. Splenius cervicis) begins on the spinous processes of III-IV thoracic vertebrae. It is attached to the posterior tubercles of the transverse processes of two or three upper cervical vertebrae. The muscle covers the back of the beginning of the muscle bundles raising the scapula. Behind her is a trapezius muscle.
The muscle, straightening the spine (m. Erector spinae) - the strongest of the autochthonous muscles of the back, extends all over the spine - from the sacrum to the base of the skull. It lies anterior to the trapezoidal, rhomboid, posterior jagged muscles, the widest mouse of the back. Behind the muscle, straightening the spine, is covered with a superficial leaf of the lumbosacral fascia.
Muscle, straightening the spine
The ileal-rib muscle (m. Iliocostalis) is the most lateral part of the muscle that straightens the spine. This muscle begins on the iliac crest, the inner surface of the superficial lumbar pectoral fascia. Muscle bundles pass upward along the posterior surface of the ribs laterally from their corners to the transverse processes of the lower (VII-IV) cervical vertebrae. Accordingly, the arrangement of individual parts of the muscle is subdivided into the ileal-rib muscle of the waist, the ileal-rib muscle of the breast and the ileal-rib muscle of the neck.
The longest muscle (m. Longissimus) is the largest of the three muscles that form the muscle that straightens the spine.
The spinal muscle (m. Spinalis) is the most medial of the three parts of the muscle that straightens the spine. The muscle is directly attached to the spinous processes of the thoracic and cervical vertebrae. This muscle is excreted by the spinous muscle of the breast, the spinous neck muscle and the spinous muscle of the head.
The transverse-awned muscle (m. Transversospinalis) is represented by a set of layered muscular bundles that run obliquely upward from the lateral in the medial direction from the transverse processes to the spinous processes of the vertebrae. The muscle bundles of the transverse-awned muscle are of unequal length and, spreading through a different number of vertebrae, form separate muscles: semisolid, multi-parted and rotator muscles.
Particle muscles (mm. Multiridi) are muscle-tendon bundles that begin on the transverse processes of the underlying vertebrae and attach to the spinous processes of the overlying ones.
Muscles-rotators of the neck, chest and waist (mm. Rotatores cervicis, thoracis et lumborum) are located in the deepest layer of the musculature of the back, in the furrow between the spinous and transverse processes. These muscles are better expressed within the thoracic spine. Accordingly, the length of the bundles, they are divided into long and short.
Muscles-rotators of the neck, chest and lower back
The muscles lifting the ribs (mm. Levatores costarum) are divided into short and long. Short muscles occupy the posterior segments of the intercostal spaces medially from the outer intercostal muscles.
The intermuscular muscles of the neck, chest and waist (mm., Interspinales cervicis, thoracis and lumborum) connect the spinous processes of the vertebrae with each other, beginning from the second cervical and below. They are better developed in the cervical and lumbar spine, which are characterized by the greatest mobility. In the thoracic part of the spine, the interstitial muscles are weakly expressed (may be absent).
Mezhostistye muscles of the neck, chest and lower back
The intersporeal muscles of the waist, chest and neck (mm., Intertransversari lumborum, thoracis et cervicis) are formed by short beams connecting the transverse processes of adjacent vertebrae, are better expressed at the level of the lumbar and cervical spine. The interdigitic muscles of the waist are divided into lateral and medial muscles.
Interdigitus muscles of waist, chest and neck
The suboccipital muscles (mm. Suboccipitales) include the large posterior rectus muscle of the head, the small posterior rectus muscle of the head, the upper and lower oblique muscles of the head. These muscles are located deep under the semi-wavy, longest and belt muscles of the head. Suboccipital muscles restrict the suboccipital triangular space (trigonum suboccipitile), which contains the vertebral artery, the posterior branch of the first cervical spinal nerve, the posterior arch of the atlant and the posterior atlanto-occipital membrane.
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