Internal Abdominal Oblique

Original Editor - Nikhil Benhur Abburi

Top Contributors - Nikhil Benhur Abburi

Description

Internal oblique

Internal abdominal oblique is a muscle found on the lateral side of the abdomen. It is broad and thin. it forms one of the layers of the lateral abdominal wall along with external oblique on the outer side and transverse abdominis on the inner side. Its fibers are obliquely oriented hence the name. It helps maintain the abdominal pressure and movements of the trunk along with the other muscles.

Origin

Lateral two-thirds of the inguinal ligament, anterior two-thirds of the intermediate line of the iliac crest, thoracolumbar fascia[1]

Insertion

Lower four ribs, abdominal aponeurosis of linea alba, crest of pubis[1]

Nerve

  • Ventral rami of intercostal nerves(T 7-T 11),
  • ilioinguinal nerve( L1)

Artery

It receives blood supply from

  • Lower posterior intercostal and subcostal arteries,
  • superior and inferior epigastric arteries,
  • superficial and deep circumflex arteries,
  • posterior lumbar arteries

Function

Internal abdominal oblique flexes the trunk when bilaterally contracted and lateral flexion upon unilateral contraction, compression causes increase in the intraabdominal pressure[1]

Clinical relevance

Weakness of internal abdominal oblique along with other abdominal muscles increase risk on abdominal hernias

Assessment

[2]

Resources

  1. 1.0 1.1 1.2 Kenhub Human anatomy, Abdomen and pelvis available on https://www.kenhub.com/en/library/anatomy/internal-abdominal-oblique-muscle ( accessed on 30-04-2020)
  2. MMT Manual muscle test internal and external obliques Dr. Bryan - Physical Therapist.. Available from: https://www.youtube.com/watch?v=KAX_CT98yKs[last accessed 30/4/2020]