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Obliquus externus abdominis

Contents

Anatomy

External oblique - anterior
External oblique - anterolateral
External oblique - lateral

General information

  • This section is strictly limited to anatomy, you might be looking for clinical relevant information which is found under the clinical chapters -- muscles section, click here to go to that page

Position

  • Superficial

Origin

  • 5.-12 ribs

Insertion

  • Crista iliaca anterior
  • Crista pubis
  • Aponeurosis abdominis (ends at the linea alba)

Main function

  • Trunk
    • Flexion
    • Lateral flexion
    • Contralateral rotation
  • Pelvis
    • Posterior tilt

Secondary function

  • Pelvis
    • Elevation
    • Ipsilateral rotation
  • Abdominal content
    • Compression

Nerve innervation

  • Segmental
    • Th7-Th12

Arterial supply

  • Subcostal artery
  • Posterior intercostal artery
  • Deep circumflex iliac artery
  • Inferior epigastric artery

Palpation

  • Patient position
    • Supine
  • Place a pillow beneath the patient's knees so that the hips are passively flexed
  • Palpate the anterolateral aspect of the stomach, between the ilium and lower ribs
  • Ask the patient to actively rotate the upper body to the opposite side while you feel for the contraction

Strength test

  • Patient position
    • Supine
  • Give resistance in a downard and diagonal direction towards the front of the shoulder
  • The patient is moving in rotation towards the resistance