Primary action is extorsion; secondary action is elevation; tertiary action is abduction (i.e. it extorts the eye and moves it upward and outward). The field of maximal inferior oblique elevation is in the adducted position.
Passing lateralward, backward, and upward, between the inferior rectus and the floor of the orbit, the inferior oblique inserts onto the scleral surface between the inferior rectus and lateral rectus.
It is the only muscle of eye movement whose origin is not on the common tendonous ring (annulus of Zinn).
"Overaction" of the inferior oblique muscle is a commonly observed component of childhood strabismus, particularly infantile esotropia and exotropia. Because true hyperinnervation is not usually present, this phenomenon is better termed "elevation in adduction".
Studies from National Taiwan University, Institute of Molecular and Cellular Biology reveal new findings on life sciences.
Jul 15, 2009; A new study, 'The transcription factor Six1a plays an essential role in the craniofacial myogenesis of zebrafish,' is now...