Spine and Thorax muscle OIA

Spinalis — Origin

Spinous processes of lower cervical and upper thoracic vertebrae

Spinalis — Insertion

Spinous processes of upper thoracic and cervical vertebrae

Spinalis — Action

Bilateral: extends vertebral column; Unilateral: lateral flexion of vertebral column to same side

Spinalis — Innervation

Posterior rami of spinal nerves

Longissimus — Origin

Transverse processes of lower thoracic and upper lumbar vertebrae

Longissimus — Insertion

Transverse processes of upper thoracic and cervical vertebrae; mastoid process of temporal bone

Longissimus — Action

Bilateral: extends vertebral column/head; Unilateral: lateral flexion of vertebral column/head to same side

Longissimus — Innervation

Posterior rami of spinal nerves

Iliocostalis — Origin

Common tendon from iliac crest, sacrum, and lumbar spinous processes

Iliocostalis — Insertion

Angles of ribs and transverse processes of cervical vertebrae

Iliocostalis — Action

Bilateral: extends vertebral column; Unilateral: lateral flexion of vertebral column to same side

Iliocostalis — Innervation

Posterior rami of spinal nerves

Quadratus Lumborum — Origin

Iliolumbar ligament and posterior iliac crest

Quadratus Lumborum — Insertion

12th rib and transverse processes of L1-L4

Quadratus Lumborum — Action

Unilateral: lateral flexion of vertebral column to same side; Bilateral: extends lumbar spine; fixes 12th rib during respiration

Quadratus Lumborum — Innervation

Anterior rami of T12-L4 spinal nerves

Rectus Abdominis — Origin

Pubic crest and pubic symphysis

Rectus Abdominis — Insertion

Xiphoid process and costal cartilages of ribs 5-7

Rectus Abdominis — Action

Flexes trunk; compresses abdominal contents; assists forced expiration

Rectus Abdominis — Innervation

Anterior rami of T6-T12 spinal nerves

External Oblique — Origin

External surfaces of ribs 5-12

External Oblique — Insertion

Linea alba, pubic tubercle, and anterior half of iliac crest

External Oblique — Action

Unilateral: rotates trunk to opposite side and laterally flexes trunk; Bilateral: flexes trunk and compresses abdominal contents

External Oblique — Innervation

Anterior rami of T7-T12 spinal nerves

Internal Oblique — Origin

Thoracolumbar fascia, anterior two-thirds of iliac crest, and lateral half of inguinal ligament

Internal Oblique — Insertion

Internal surfaces of ribs 10-12, linea alba, and pubis

Internal Oblique — Action

Unilateral: rotates trunk to same side and laterally flexes trunk; Bilateral: flexes trunk and compresses abdominal contents

Internal Oblique — Innervation

Anterior rami of T7-L1 spinal nerves

Transversus Abdominis — Origin

Internal surfaces of costal cartilages of ribs 7-12, thoracolumbar fascia, iliac crest, and lateral third of inguinal ligament

Transversus Abdominis — Insertion

Linea alba and pubic crest

Transversus Abdominis — Action

Compresses abdominal contents and stabilizes the trunk

Transversus Abdominis — Innervation

Anterior rami of T7-L1 spinal nerves