Spine - Muscles of the trunk and movements

Question 1

What are the muscles of the abdomen (most superficial to most deep)?

Answer 1

External oblique
Internal oblique
Rectus abdominis
Transverse abdominis muscle

Question 2

What is the action, origin, and insertion of the external oblique muscle?

Answer 2

Action - Flexes, laterally flexes and rotates trunk (towards opposite side)
Origin - Side of rib cage/thoracic cage
Insertion - ASIS, anterior half of iliac crest, pubic crest and pubic tubercle

Question 3

What is the action, origin, and insertion of the internal oblique muscle?

Answer 3

Action - Flexes, laterally flexes, and rotates trunk; compresses and provides structural support to adjacent abdominal structures
Origin - Thoracolumbar fascia, iliac crest
Insertion - Inferior margins of 10th-12th ribs and adjacent costal cartilages, linea alba, pecten pubis

Question 4

What is the action, origin, and insertion of the rectus abdominis muscle?

Answer 4

Action - Flexes trunk; compresses and provides structural support to adjacent abdominal structures
Origin - Pubic rest and symphysis
Insertion - Xiphoid process and costal cartilages of 5th-7th ribs

Question 5

What is the action, origin, and insertion of the transverse abdominis muscle?

Answer 5

Action - Compresses and provides structural support to adjacent abdominal structures
Origin - Costal cartilages of 7th-12th ribs, thoracolumbar fascia, iliac crest, and inguinal ligament
Insertion - Linea alba, pubic crest, pecten pubis

Question 6

What are the muscles of the back (most superficial to most deep)?

Answer 6

Trapezius and Latissimus dorsi (global movers)
Irrectus Spinu (function - to keep spine straight)
Spinalis
Longissimus
Iliocostalis
Splenius capitis
Splenius cervices
Semispinalis capitis
Montifitus
Quadratus lumborum