Related Experiment Video
Updated: Jun 23, 2026

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle
Published on: June 2, 2018
Relationship of inferior oblique overaction to muscle bulk and position
Abbas Bagheri1, Mohammad Eshaghi, Shahin Yazdani
1Department of Ophthalmology, Labbafinejad Medical Center, Shaheed Beheshti Medical University, Tehran, Iran. abbasbagheri@yahoo.com
Introduction:
The possible association between inferior oblique muscle overaction and inferior oblique muscle mass has been a matter of speculation. This study was performed to evaluate the anatomical position of the inferior oblique muscle and to determine any association between muscle mass and inferior oblique muscle overaction.
Methods:
In this observational case series, eyes undergoing primary surgery for inferior oblique overaction underwent measurement of inferior oblique muscle borders distance from the limbus and muscle belly circumference.
Results:
Overall, 78 eyes of 51 patients with mean age of 18.3 +/- 12.3 years (range, 1-48) were evaluated. The mean distance of the anterior margin of the inferior oblique muscle from the limbus was 16.3 mm +/- 1.8 mm. The distance for the posterior margin was 20.8 mm +/- 1.9 mm. Average muscle circumference was 10.7 mm +/- 0.9 mm (range, 9 to 13). Inferior oblique muscle overaction and muscle belly circumference were not significantly correlated (p = 0.8).
Conclusion:
There was no detectable correlation of inferior oblique overaction with either muscle position or circumference.
Related Concept Videos
Muscles of the Eye
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and rotating...
Accessory Structures of the Eye
Muscles for Facial Expressions
Muscle Coordination and Action
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement.
Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
Naming Skeletal Muscles
The key factors used in naming muscles include:

