© 2015 Brent Brookbush All illustrations courtesy of – Wikipedia.org

Quick Reference: Study Guide

The Spine

Cervical Vertebrae – The 7 vertebrae of the neck.

Lordotic Curvature

Thoracic Vertebrae – The 12 vertebrae with bony

attachments to the 12 pair of ribs.

Kyphotic Curvature

Lumbar Vertebrae – The 5 vertebrae of the low back

Lordotic Curvature

External Obliques

Origin: 8 lowest ribs

Insertion: Iliac crest, rectus sheath, inguinal ligament

Joints crossed: Lumbar Spine

Actions: Flexion, lateral flexion and contralateral

rotation

© 2015 Brent Brookbush All illustrations courtesy of – Wikipedia.org

Rectus Abdominis

Origin: Costal cartilage of ribs 5-7

Insertion: Pubic crest and pubic symphysis

Joint crossed: Lumbar Spine

Action: Flexion

Internal Obliques

Origin: Thoracolumbar fascia, iliac crest, lateral 2/3

of inguinal ligament

Insertion: Lower 4 ribs, and rectus sheath

Joint crossed: Lumbar spine

Actions: Flexion, lateral flexion and ipsilateral

rotation

© 2015 Brent Brookbush All illustrations courtesy of – Wikipedia.org

Transverse Abdominis

Origin: Last 6 ribs, thoracolumbar aponeurosis, iliac

crest

Insertion: Linea alba and superior pubic ramus

Joint crossed: Lumbar Spine

Actions: Lumbar Stabilization (via increased intra-

abdominal pressure and increased thoracolumbar

fascia stiffness)

Erector Spinae

Origin: Iliac crest and sacrum

Insertion: All transverse and spinous processes, from

lumbar spine to skull

Joint crossed: Lumbar spine

Actions: Extension, lateral flexion, and potentially

ipsilateral rotation

© 2015 Brent Brookbush All illustrations courtesy of – Wikipedia.org

Multifidus

Origin: Posterior surface of the sacrum, the dorsal end

of the iliac crest, the mamillary and transverse

processes of the lumbar and the thoracic vertebrae and

the articular processes of the 4th - 7th cervical

vertebrae.

Insertion: Spinous processes of all vertebrae, except

the atlas

Joint crossed: Lumbar spine

Actions: Extension, lateral flexion, and contralateral

rotation

Special Note: Due to segmental innervation, these

muscles may be particularly important for segmental

stabilization of the lumbar vertebrae.

Quadratus Lumbroum

Origin: 12th rib and lumbar transverse processes

Insertion: Iliac crest

Joint crossed: Lumbar spine

Actions: Lateral flexion