Back muscles - medial tract

General information

The medial tract is innervated via the medial branches of the Rr. dorsales of the spinal nerves. It is divided into the spinal (Mm. interspinales and M. spinalis) and the transversospinal system (Mm. rotatores breves and longi, M. multifidus and M. semispinalis).

A schematic drawing of the muscles (Mm. interspinales, Mm. rotatores breves and longi etc.) can be displayed by clicking on the respective name in the "WebViewer".

Spinal system

	Mm. interspinales	M. spinalis
origin	1) Mm. interspinales cervicis: spinous processes (Proc. spinosus) of the lower cervical vertebra 2) Mm. interspinales lumborum: Proc. spinosus of the lower lumbar vertebra	3) M. spinalis thoracis: Proc. spinosus of the 10th-12th thoracic vertebra and of the 1st-3rd lumbar vertebra 4) M. spinalis cervicis: Proc. spinosus of the 1st and 2nd thoracic vertebra and the 5th to 7th cervical vertebra
insertion	1) next higher Proc. spinosus of the cervical spine 2) next higher Proc. spinosus of the lumbar spine	3) spinous processes of the upper thoracic vertebra 4) spinous processes of the 2nd and 3rd cervical vertebra
function	The Musculi interspinales has a supporting function in an upright posture and helps with the dorsal extension of the cervical and lumbar spine.	One-sided contraction causes a lateral flexion of the thoracic and cervical spine to the ipsilateral side, on both sides the function of the muscle is the dorsal extension of the cervical spine and thoracic spine.

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Transversospinales System

	Mm. rotatores breves u. longi	M. multifidus	M. semispinalis
origin	5) Mm. rotatores breves: transverse process (Proc. transversus) the thoracic vertebra 6) Mm. rotatores longi: Proc. transversus the thoracic vertebra	7) runs between Proc. transversus and Proc. spinosus of the higher vertebra within the entire spine (2nd cervical vertebral spine up to Os sacrum), the deep muscle parts skip two vertebrae, the superficial parts skip up to 5 vertebrae	8) M. semispinalis thoracis: Proc. transversus of the 6th-12th thoracic vertebra 9) M. semispinalis cervicis: Proc. transversus of the 1st-6th thoracic vertebra 10) M. semispinalis capitis: Proc. transversus of the 6th thoracic to 3rd cervical vertebra
insertion	5) next higher Proc. spinosus of the thoracic spine 6) next but one Proc. spinosus within the thoracic spine	7) see origin	8) Proc. spinosus of the 4th thoracic to 6th cervical vertebra 9) Proc. spinosus of the 2nd-7th cervical vertebra 10) medial area of the Os occipitale between Linea nuchalis superior and inferior
function	Rotation of the spinal column to the contralateral side in one-sided contraction and dorsal extension of the thoracic spine in bilateral activation	Rotation of the spine to the contralateral side and lateral flexion to the ipsilateral side in case of one-sided contraction, dorsal extension in case of bilateral contraction	Lateral flexion to the ipsilateral side and rotation to the contralateral side in one-sided contraction, dorsal extension of the cervical spine, thoracic spine and head in two-sided contraction

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Further links

Exercises

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