Erector Spinae Muscles

Spinalis Thoracis, Spinalis Cervicis and Spinalis Capitis:

ORIGIN: Spines of upper lumbar and lower thoracic vertebrae

INSERTION: Spines of upper thoracic and cervical vertebrae

ACTION: 1. Extends Vertebral Column

2. Assists in maintaining an erect spine

3. Assists in bending backwards, bending sideways & rotating the spine

to the same side

BLOOD SUPPLY: Muscular branch of the aorta

NERVOUS INNERVATIONS: Spinal nerves (dorsal rami)

SPINALIS MUSCLES

Spinalis Cervicis

Spinalis Thoracis

Note: Spinalis Capitis NOT shown

Spinalis Capitis

Spinalis Capitis

Spinalis

SPINALIS MUSCLES

Spinalis Cervicis

Spinalis Cervicis

Spinalis Thoracis

Transversospinal Muscles

Long Rotators and Short Rotators

ORIGIN: Transverse process of one vertebrae

INSERTION: Base of spinous process

- (Long Rotators): skips one vertebra to insert on the base of spinous process of vertebra above

- (Short Rotators): base of spinous process of vertebra immediately above.

ACTION: Rotate to opposite side & bilateral extension

BLOOD SUPPLY: Muscular branches of the aorta

NERVE SUPPLY: Dorsal Rami of spinal nerves

LONG & SHORT ROTATORS

Rotators

LONG & SHORT ROTATORS

Transversospinal Muscles

Semispinalis Thoracis, Semispinalis Cervicis & Semispinalis Capitus

ORIGIN: Transverse processes of C7-T12

INSERTION: Occipital bone (capitis) and spinous processes of cervical (cervicis) and thoracic vertebrae T1 to T4 (thoracis)

ACTION: Extends vertebral column and head, and rotates them in opposite sides; acts synergistically with sternocleidomastoid muscle of opposite side.

BLOOD SUPPLY: Muscular branches of the aorta

NERVE SUPPLY: Spinal nerves (dorsal rami)

CapitisCervicis

Thoracis

SEMISPINALIS MUSCLES

Capitis

Cervicis

Thoracis

Multifidus

CapitisCervicis

SEMISPINALIS MUSCLES

Transversospinal MusclesMultifidus

ORIGIN: 1. Cervical Region: from articular process of lower cervical vertebrae 2. Thoracic Region: from transverse process of all thoracic vertebrae 3. Lumbar Region: - lower portion of dorsal sacrum - deep surface of tendenous origin of erector spinae - mamillary processes of all lumbar vertebrae INSERTION: Spinous process of all vertebrae extending from L5-C2 (skipping 1-

3 segments)ACTION: Bilaterally extends vetebral column, controls lateral flexion to side

opposite contraction (eccentric for stability), and unilaterally rotate vertebral bodies (column) to opposite side

BLOOD SUPPLY: Muscular brances of aortaNERVE SUPPLY: Dorsal Rami of Spinal nerves

Multifidus

MULTIFIDUS

MULTIFIDUS

Segmental Muscles

Interspinalis

ORIGIN: Spinous processes of each vertebrae

INSERTION: The spinous process of the vertebra immediately above

ACTION: Extension of the vertebrae segments

BLOOD SUPPLY: Muscular branches of the aorta

NERVE SUPPLY: Dorsal Rami of spinal nerves

INTERSPINALIS

Interspinalis

Interspinalis

INTERSPINALIS