Muscles of the back (intrinsic muscles of the spine)

Transversospinales muscle group is a deep group of back muscles that lies deep to the Erector Spinae. It consists of 3 major subgroups:

semispinalis, multifidus and rotatores

Splenius Capitis (L)

*1 of the 2 muscles of the Splenius (the splenius cervicis and splenius capitis); an intrinsic muscle of the back that assists in movements of the vertebral column and head. This muscle is often classified with the muscles of the posterior triangle of the neck *Origin: Lower half of the ligamentum nuchae and spinous processes of vertebrae CO7-TO3 *Insertion:Mastoid process of the temporal bone and the rough surface of the occipital bone *Muscle Action: Extension and lateral flexion of the neck and spine; ipsilateral rotation of the head (turning the head toward the side of the body that contains the muscles performing the action)

Splenius Cervicis (L)

*1 of the 2 muscles of the Splenius (the splenius cervicis and splenius capitis); an intrinsic muscle of the back that assists in movements of the vertebral column and head. This muscle is often classified with the muscles of the posterior triangle of the neck *Origin:Spinous processes of vertebrae TO3-TO6 *Insertion: Mastoid process *Muscle Action:Extension and lateral flexion of the neck and spine; ipsilateral rotation of the head (turning the head toward the side of the body that contains the muscles performing the action)

Rectus Capitis Anterior (L)

*1 of the 2 rectus capitis muscles (rectus capitis anterior, rectus capitis lateralis); a short, flat prevertebral muscle, situated behind the longus capitis muscle, that assists in movements of the neck. *Origin:Upper surface of the transverse process of the atlas (C01) *Insertion:Inferior surface of the base of the occipital bone *Muscle Action: Flexion of the neck

Rectus Capitis Lateralis (L)

*1 of the 2 rectus capitis muscles (rectus capitis anterior, rectus capitis lateralis); a short, flat prevertebral muscle, situated behind the longus capitis muscle, that assists in movements of the neck. *Origin:Upper surface of the transverse process of the atlas (C01) *Insertion:Inferior surface of the base of the occipital bonea short, flat prevertebral muscle, situated behind the occipital bone, that assists in movements of the vertebral column. *Origin: Upper surface of the transverse process of the atlas (C01) *Insertion: Beneath the surface of the jugular process of the occipital bone *Muscle Action: Flexion and lateral flexion of the neck; lateral flexion of the spine ​

Iliocostalis Lumborum (L)

*1 of the 3 iliocostalis muscles (the iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis) *Origin: lliac crest and the lateral portion of the common erector spinae tendon *Insertion: Inferior borders of the angles of the lower 6-7 ribs *Muscle Action: Extension and lateral flexion of the spine

lliocostalis cervicis (l)

*1 of the 3 iliocostalis muscles (the iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis);the iliocostalis muscle is part of the erector spinae *Origin:Ribs 3-6 *Insertion:Transverse processes of vertebrae C04-C06 *Muscle Action: Extension and lateral flexion of the spine

lliocostalis thoracis (L)

*1 of the 3 iliocostalis muscles (the iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis);the iliocostalis muscle is part of the erector spinae *Origin: Upper borders of the angles of ribs 7-12, medial to the tendons of insertion of the iliocostalis lumborum *Insertion: Into the upper borders of the angles of ribs 1-6 and into the back of the transverse process of vertebra C07 *Muscle Action: Extension and lateral flexion of the spine

Longus Colli (superior oblique)

*1 of the 3 muscles of the Longus Colli (vertical, inferior oblique, and superior oblique fibers)

Longus Colli (vertical)

*1 of the 3 muscles of the Longus Colli (vertical, inferior oblique, and superior oblique fibers) *Origin: Front of the bodies of vertebrae C05-TO3 *Insertion: Front of the bodies of vertebrae C02-C04 *Muscle Action: Flexion of the neck

Longus Colli (inferior oblique) (L)

*1 of the 3 muscles of the Longus Colli (vertical, inferior oblique, and superior oblique fibers) *Origin: Front of the bodies of vertebrae TO1-TO3 *Insertion: Anterior tubercles of the transverse processes of vertebrae C05 and C06 *Muscle Action: Flexion of the neck

Spinalis cervicis (L)

*1 of the three Spinalis muscles (spinalis thoracis (dorsi), spinalis cervicis, and spinalis capitis); the spinalis is part of the erector spinae **Origin: Ligamentum nuchae, spinous process of vertebra C07, and sometimes from the spinous processes of vertebrae T01 and TO2 *Insertion: Spinous processes of vertebrae C02-C05 Action: Extension and lateral flexion of the spine

Spinalis Thoracis

*1 of the three Spinalis muscles (spinalis thoracis (dorsi), spinalis cervicis, and spinalis capitis); the spinalis is part of the erector spinae *Origin: Spinous processes of vertebrae T11-L02 *Insertion: Spinous processes of the upper thoracic vertebrae by 4-8 tendons *Muscle Action: Extension and lateral flexion of the spine

Semispinalis

*The semispinalis (r, I) is a series of transversospinalis muscles of the back, located between the transverse and spinous processes, that assist in movements of the vertebral column and head. They are composed of three divisions (moving upward): the semispinalis thoracis (dorsi) semispinalis cervicis, and semispinalis capitis,which has lateral and medial fascicles

Semispinalis capitis (medial fascicle), (L)

*1 of the three semispinalis muscles (semispinalis thoracis (dorsi) semispinalis cervicis, and semispinalis capitis,which has lateral and medial fascicles); the semispinalis is part of the transversospinalis muscles *Origin: Tips of the transverse processes of the upper 6-7 thoracic vertebrae and vertebra C07 and from the articular processes of vertebrae C04-C06. *Insertion: Between the superior and inferior nuchal lines of the occipital bone *Muscle Action: Extension of the spine; extension and lateral flexion of the neck

Semispinalis capitis (lateral fascicles) (L)

*1 of the three semispinalis muscles (semispinalis thoracis (dorsi) semispinalis cervicis, and semispinalis capitis,which has lateral and medial fascicles); the semispinalis is part of the transversospinalis muscles *Origin: Tips of the transverse processes ofnthe upper 6-7 thoracic vertebrae and vertebra C07 and from the articular *Insertion: Between the superior and inferior nuchal lines of the occipital bone *Muscle Action: Extension of the spine; extension and lateral flexion of the neck

Semispinalis Cervicis (l)

*1 of the three semispinalis muscles (semispinalis thoracis (dorsi) semispinalis cervicis, and semispinalis capitis,which has lateral and medial fascicles); the semispinalis is part of the transversospinalis muscles *Origin: Transverse processes of vertebrae TO1-TO6 *Insertion: Spinous processes of vertebrae C02-C07 *Muscle Action: Extension of the neck and spine; contralateral rotation of the head (turning the head away from the side of the body that contains the muscles performing the action)

semispinalis thoracis (l)

*1 of the three semispinalis muscles (semispinalis thoracis (dorsi) semispinalis cervicis, and semispinalis capitis,which has lateral and medial fascicles); the semispinalis is part of the transversospinalis muscles Origin: Transverse processes of vertebrae TO6-T12 Insertion: Spinous processes of vertebrae CO6-T04 Muscle Action: Extension of the spine

Longissimus thoracis (L)

*Grouped within the Erector Spinae; 1 of the 3 Longissimus muscles (longissimus thoracis, longissimus cervicis, and longissimus capitis.) *Origin: The whole length of the posterior surfaces of the transverse processes and the accessory processes of the lumbar vertebrae and the lumbodorsal fascia *Insertion: By rounded tendons, into the tips of the transverse processes of all the thoracic vertebrae, and by fleshy processes, into the lower 910 ribs between their tubercles and angles. *Muscle Action: Extension and lateral flexion of the spine

Longissimus Cervicis (l)

*Grouped within the Erector Spinae; 1 of the 3 Longissimus muscles (longissimus thoracis, longissimus cervicis, and longissimus capitis.) *Origin: Transverse processes of vertebrae TO1-T05 *Insertion; Posterior margin of the mastoid process, beneath the splenius capitis and sternocleidomastoid *Muscle Action: Extension and lateral flexion of the neck and spine; ipsilateral rotation of the head (turning the head toward the side of the body that contains the muscles performing the action)

Obliquus Capitis Inferior (L)

*Larger of the 2 obliquus Capitis muscles; part of the suboccipital muscle group

longissimus capitis (l)

*Origin: Transverse processes of the upper 4-5 thoracic vertebrae and the articular processes of the lower 3-4 cervical vertebrae *Insertion:Posterior margin of the mastoid process, beneath the splenius capitis and sternocleidomastoid *Muscle Action: Extension and lateral flexion of the neck and spine; ipsilateral rotation of the head (turning the head toward the side of the body that contains the muscles performing the action) ​

The iliocostalis muscle

*The iliocostalis muscle (r, I) is a muscle of the back, located in the lateral column of the erector spinae, that assists in movements of the vertebral column. It is composed of three divisions (moving upward): the iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis

Longis Capitis

*The longus capitis (r, l) is a prevertebral muscle, situated at the base of the occipital bone, that assists in movements of the neck. It is short and broad above and narrow below. *Origin: Anterior tubercles of the transverse processes of vertebrae C03-C06 *Insertion: Basilar part of the occipital bone *Muscle Action: Flexion of the neck

Longus Colli muscles

*The longus colli (r, I) is a prevertebral muscle situated at the anterior part of the vertebral column, that assists in movements of the neck. It is pointed and narrow at either end, broad in the middle, and consists of three portions: the vertical, inferior oblique, and superior oblique fibers.

Multifidus (L)

*The multifidus (r, I) is an intrinsic transversospinalis muscle of the deep back that assists in movements of the vertebral column and head. It consists of many fasciculi that fill the groove on either side of the spinous process, extending from the axis (C02) to the sacrum. It spans three joint segments and works to stabilize each joint *Origin: Sacrum, posterior superior iliac spine mammillary processes of the lumbar vertebrae, transverse processes of the thoracic vertebrae, and articular processes of vertebrae C04-C07 *Insertion: Spinous process of the vertebra 2-4 above the origin *Muscle Action: Stabilization of the vertebrae in local movements of the vertebral column; rotation of the thoracic spine; extension of the neck and spine; contralateral rotation of the head (turning the head away from the side of the body that contains the muscles performing the action)

Rotatores thoracic Longi (r,l)

*The rotatores thoracis breves and longi (r, l) are intrinsic muscles of the deep back that assist in movements of the vertebral column and head Origin: Transverse process of each thoracic vertebra Insertion: Spinous process of the vertebra two above each origin Muscle Action: Rotation of the thoracic spine; extension of the spine; contralateral rotation of the head (turning the head away from the side of the body that contains the muscles performing the action)

Rotatores thoracic breves (l)

*The rotatores thoracis breves and longi (r, l) are intrinsic muscles of the deep back that assist in movements of the vertebral column and head. *Origin: Transverse process of each thoracic vertebra *Insertion: Spinous process of the vertebra above each origin *Muscle Action: Rotation of the thoracic spine; extension of the spine; contralateral rotation of the head (turning the head away from the side of the body that contains the muscles performing the action)

The Spinalis Muscle

*The spinalis (r, I) is a muscle of the back located in the medial column of the erector spinae, that assists in movements of the vertebral column. It is composed of three divisions (moving upward): the spinalis thoracis (dorsi), spinalis cervicis, and spinalis capitis. The spinalis capitis is often fused with the semispinalis capitis, and the spinalis thoracis is difficult to distinguish from the sacrospinalis, which it continues from medially

Rectus Capitis Posterior Major (L)

*part of the suboccipital muscle group; situated right at the base of the occipital bone *Origin: Spinous process of the axis (C02) *Insertion: Lateral part of the inferior nuchal line of the occipital bone *Muscle Action: Extension of the neck and spine; ipsilateral rotation of the head (turning the head toward the side of the body that contains the muscles performing the action)

Rectus Capitis Posterior Minor (L)

*part of the suboccipital muscle group;situated at the base of the occipital bone above the atlas *Origin: Tubercle on the posterior arch of the atlas (C01) *Insertion: Medial part of the inferior nuchal line of the occipital bone and the surface between it and the foramen magnum *Muscle Action: Extension of the neck and spine; now considered to be sensory in function

Obliquus Capitis Inferior (L)

*smaller of the 2 obliquus capitis muscles ; part of the suboccipital muscle group *Origin: Tubercle on the posterior arch of the atlas (C01) *Insertion: Medial part of the inferior nuchal line of the occipital bone and the surface between it and the foramen magnum *Muscle Action: Extension of the neck and spine; now considered to be sensory in function

The Erector Spinae consists of which muscles?

Longissimus, iliocostalis, spinalis

Rotatores

Rotatores: The rotatores thoracis breves and longi (r, l) are intrinsic muscles of the deep back that assist in movements of the vertebral column and head. Somewhat quadrilateral in shape, these muscles are found only in the thoracic region (T01-T12), and there are 11 on each side of the spine

The deep muscles of the back, also called the intrinsic muscles of the spine, are further categorized into the following groups:

The erector spinae (extensor spinae,sacrospinalis) (r, I), the transversospinalis (r, I) suboccipital (r, I), splenius (r, I), and prevertebral (r, I)

The suboccipital muscles are a group of four muscles located inferior to the external occipital prominence of the skull and consists of what 4 muscles?

The four muscles are the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis inferior, and obliquus capitis superior

Longissimus

The longissimus muscle (r, I) is a muscle of the back, located in the intermediate column of the erector spinae, that assists in movements of the vertebral column and head. It is composed of three divisions (moving upward): longissimus thoracis (dorsi), longissimus cervicis, and longissimus capitis

Splenius consists of what muscles?

The splenius (r, l) is an intrinsic muscle of the back that assists in movements of the vertebral column and head. This muscle is often classified with the muscles of the posterior triangle of the neck. It is composed of two divisions (moving upward): the splenius cervicis and splenius capitis.

Prevertebral back muscles include:

the rectus capitis anterior, rectus capitis lateralis, longus capitis, and longus colli muscles