INTERNAL ABDOMINAL OBLIQUE

Origin

Lumbar fascia, ant two thirds of iliac crest and lat two thirds of inguinal lig

Action

Supports abdominal wall, assists forced respiration, aids raising intraabdominal pressure & , with muscles of other side , abducts and rotates trunk. Conjoint tendon supports post wall of inguinal canal

Insertion

Costal margin, aponeurosis of rectus sheath (ant and post ), conjoint tendon to public crest and pectineal line

Nerve

Ant primary rami (T7-12) (conjoint tendon ilioinguinal N (L1))