1.2 Individual Muscle Function Muscle Primary action Secondary and Tertiary action Medial rectus Adduction None Lateral Rectus Abduction None Superior Rectus Elevation Adduction Intorsion Inferior rectus Depression Adduction Extortion Superior oblique Intorsion Depression, Abduction Inferior oblique Extorsion Elevation. abduction 复大学附属眼耳鼻喉科医院1.2 Individual Muscle Function Muscle Primary action Secondary and Tertiary action Medial Rectus Adduction None Lateral Rectus Abduction None Superior Rectus Elevation Adduction,Intorsion Inferior Rectus Depression Adduction,Extortion Superior Oblique Intorsion Depression,Abduction Inferior Oblique Extorsion Elevation,Abduction