Spinal Flexors

Question 1

Rectus Abdominis

Answer 1

Origin: Pubic symphysis, pubic crest
Insertion: Xiphoid process of sternum, ribs 5, 6, 7
Action: Flex. of thoracic and lumbar spine to 35 degrees, post. rotates pelvis by 10 degrees, increases intra-abdominal pressure

Question 2

Internal Obliques

Answer 2

Origin: Iliac crest, lumbar fascia
Insertion: Ribs 8, 9, 10, linea alba

Question 3

External Obliques

Answer 3

Origin: Lower 8 ribs
Insertion: Iliac crest, linea alba
Action: When working with contralateral internal oblique, rotation of spine. When working unilaterally with internal oblique, lat. flex. of spine