1. 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)

2. SPINALIS MUSCLES Spinalis Cervicis Spinalis Thoracis Note: Spinalis Capitis NOT shown

3. Spinalis Capitis Spinalis

4. SPINALIS MUSCLES Spinalis Cervicis Spinalis Thoracis

5. 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

6. LONG & SHORT ROTATORS Rotators

8. LONG & SHORT ROTATORS

9. Transversospinal Muscles Semispinalis Thoracis, Semispinalis Cervicis & Semispinalis Capitus ORIGIN: Transverse processes of C 7 -T 12 INSERTION: Occipital bone (capitis) and spinous processes of cervical (cervicis) and thoracic vertebrae T 1 to T 4 (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)

10. Capitis Cervicis Thoracis

11. SEMISPINALIS MUSCLES

12. Capitis Cervicis Thoracis Multifidus CapitisCervicis

13. SEMISPINALIS MUSCLES

14. Transversospinal Muscles Multifidus 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 L 5 -C 2 (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 aorta NERVE SUPPLY: Dorsal Rami of Spinal nerves

15. Multifidus

16. MULTIFIDUS

18. 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

19. INTERSPINALIS Interspinalis

21. INTERSPINALIS