Spine and Thorax Main Group

Quadratus Lumborum Action

Unilaterally: Laterally tilt (elevate) the pelvis, laterally flex the vertebral column to the same side, assist to extend the vertebral column
Bilaterally: Fix the last rib during forced inhalation and exhalation

Quadratus Lumborum Origin

Posterior iliac crest

Quadratus Lumborum Insertion

Last rib and TVP of L1-L4

Quadratus Lumborum Innervation

Lumbar plexus T12, L1,2 and 3

Diaphragm Action

Draw down the central tendon of the diaphragm
Increase the volume of the thoracic cavity during inhalation

Diaphragm Origin

Costal attachment: Inner surface of lower 6 ribs

Lumbar attachment: Upper 2 or 3 lumbar vertebrae

Sternal attachment: Inner part of xiphoid process

Diaphragm Insertion

Central tendon

Diaphragm Innervation

Phrenic C3,4,5

Intercostals Action

External Intercostals: Draw the ribs superiorly (increasing the space of the thoracic cavity) to assist with inhalation
Internal Intercostals: Draw the ribs inferiorly (decreasing the space of the thoracic cavity) to assist with exhalation

Intercostals Origin

Inferior border of the rib above

Intercostals Insertion

Superior border of the rib below

Intercostals Innervation

Thoracic

Serratus Posterior Superior Action

Elevate ribs during inhalation

Serratus Posterior Superior Origin

Spinous processes of C7 to T3

Serratus Posterior Superior Insertion

Posterior surface of 2nd through 5th ribs

Serratus Posterior Superior Innervation

T1, 2, 3, 4

Serratus Posterior Inferior action

Depress ribs during exhalation

Serratus Posterior Inferior Origin

Spinous processes of T12-L3

Serratus Posterior Inferior Insertion

Posterior surface of 9th to 12th ribs

Serratus Posterior Inferior Innervation

T9,10, 11,12

Intertransversarii action

Unilaterally: Laterally flex vertebral column to the same side
Bilaterally: Extend the vertebral column

Intertransversarii Origin/Insertion

Cervical: spanning the transverse processes of vertebrae C2-C7
Lumbar: spanning the transverse processes of vertebrae L1-L5

Intertransversarii Innervation

Spinal

Interspinalis Action

Extend vertebral column

Interspinalis Origin/Insertion

Cervical: spanning the spinous processes of C2-T3
Lumbar: spanning the spinous processes of T12-L5

Interspinalis Innervation

Spinal