MSA2 Abdomen Muscles

  1. Rectus Abdominis
    • Origin: pubic crest; pubic symphysis
    • Insertion: Cartilage of ribs 5 -7 and xyphoid process
    • Actions: flexion of the trunk (insertion moves towards origin); tilts pelvis posteriorly (origin to insertion)
    • Nonropy
    • Superficial
  2. Quadratus Lumborum
    • Origin: Posterior iliac crest; iliolumbar ligament
    • Insertion: 12th rib; TVPs of L1 - L4
    • Bilateral action: assists in trunk extension; fixes 12th rib during respiration
    • Unilateral actions: ipsilateral lateral of trunk (insertion to origin); elevation of hip (really pelvic girdle; origin to insertion)
    • Nonropy
    • Very deep
  3. External Oblique
    • Starts where serratus anterior stops
    • Origin: External surface of lower 8 ribs
    • Insertion: Anterior iliac crest and abdominal aponeurosis
    • Bilateral action: flexion of trunk
    • Unilateral actions: ipsilateral flexion of the trunk; contralateral rotation of the trunk (contracts down and across)
    • Nonropy
    • Superficial
  4. Internal Oblique
    • Origin: Lateral inguinal ligament iliac crest; thoracolumbar aponeurosis
    • Insertion: cartilage of lower 3 ribs; abdominal aponeurosis to linea alba
    • Bilateral action: flexion of the trunk and compresses the abdominal contents
    • Unilateral action: ipsilateral lateral flexion and rotation of the trunk
    • Nonropy
    • Deep to external obliques
Card Set
MSA2 Abdomen Muscles
Muscles of the Abdomen