<prompt> Superior oblique testing for 4th nerve is done by checking its intorsion while asking the subjet to look -Straight downStraight upDown and inDown and out  <response>: superior oblique is supplied by 4 cranial nerve- trochlear. Primary action of superior oblique is intorsion also called incycloduction- rotatory movement along anteroposterior axis in which superior pole of cornea 12 o clock point moves medially.secondary actions include depression and abduction. 