Abnormal inferior oblique muscle physiology 2018-01-13T20:54:37Z The major functions of the inferior oblique muscle are extorsion (external rotation), elevation, and abduction. A functional anomaly of the inferior oblique muscle, an extraocular muscle that has its origin on the maxillary bone just posterior to the inferior medial orbital rim and lateral to the nasolacrimal canal and that is innervated by the inferior branch of the oculomotor nerve. Abnormal oblique muscle physiology