Do you have problem memorizing Extraocular Muscle Actions before this? If yes, let's apply Syah's Rule. In this post using Syah's Rule , we concern on vertical muscles actions. Why??? Lateral muscles have one action only either abduction for Lateral Rectus and adduction for Medial Rectus.
Vertical muscles have 3 muscle actions named as 1st action, 2nd action and 3rd action or in other words it's controls vertical movement (elevation or depression), torsional movement (extortion or intortion) and lateral movement (adduction or abduction). So many guys..Fenin2..Headache to remember them...
Relax guy, I'm here to make its simple using Syah's Rule..Please refer to the figure above...
- The upper muscle in red triangular which are Superior Rectus (SR) and Inferior Oblique (IO) = muscle action is elevation
- The lower muscle in green inverse triangular which are Inferior Rectus (IR) and Superior Oblique (SO) = muscle action is depression
- All 'S' muscles (Superior Muscle) = muscle action is Intortion
- All 'I' muscles (Inferior Muscle) = muscle action is Extortion
- All 'O' muscles (Oblique Muscle) = muscle action is Abduction
- All 'R' muscles (Rectus Muscle) = muscle action is Adduction
It is simple, right?...Remember of the Word, Remember of the Action.