Vertebral Column

Question 1

Flexion (antagonists on extension)

Answer 1

• Rectus abdominis
• External oblique (bilaterally)
• Internal oblique (bilaterally)
• Psoas major (with the insertion fixed)
• Iliacus (with the insertion fixed)

Question 2

Extension (antagonists on flexion)

Answer 2

• Longissimus (bilaterally)
• Iliocostalis (bilaterally)
• Multifidi (bilaterally)
• Rotatores (bilaterally)
• Semispinalis (bilaterally)
• Spinalis (bilaterally)
• Quadratus lumborum (assists)
• Interspinalis
• Intertransversarii (bilaterally)
• Latissimus dorsi (assists, when arm is fixed)

Question 3

Rotation (all unilaterally)

Answer 3

• External oblique (to the opposite side)
• Internal oblique (to the opposite side)
• Multifidi (to the opposite side)
• Rotatores (to the opposite side)

Question 4

Lateral Flexion (unilaterally to the same side)

Answer 4

• Iliocostalis
• External oblique
• Internal oblique
• Longissimus
• Quadratus lumborum
• Psoas major (assists)
• Intertransversarii
• Spinalis
• Latissimus dorsi (assists)