Inferior rectus muscle characteristics is:
- All extraocular muscles (all recti, superior oblique & lavatory palpebrae superioris) except inferior oblique arise from apex of orbitQ. Inferior rectus muscle originate from inferior edge of common tendinous ring (annulus of Zinn). It courses anteriorly, laterally and downwards along the orbital floor to inse on sclera anteriorly about 6.5 cm behind the limbusQ. Inferior rectus muscle courses between the eye ball and inferior oblique muscle (which passes beneath i. e. inferior to inferior rectus)Q prior to its inseion. Failure to dissect fascial attachments b/w inferior rectus, inferior oblique and lower rid retractors during IR recession or resection may 1/ eyelid fissure widening or narrowing, respectively.
Inseion- 6.5 cm behind limbus
Lies inferior to inferior oblique muscle
Main depressor when adducted
All