Superior Oblique (Left) (Musculus obliquus superior)
Educational content only — not medical advice.
Anatomy
The superior oblique is a fusiform muscle located in the upper medial part of the orbit. Arising from the sphenoid body, it runs anteriorly along the superomedial wall, terminates in a slender tendon that loops through the fibrocartilaginous trochlea, and then reflects posterolaterally beneath the superior rectus to insert into the posterolateral sclera. It is the longest extraocular muscle.
Origin & insertion
From the body of the sphenoid bone superomedial to the optic canal, looping through the trochlea of the frontal bone, to the posterosuperior lateral quadrant of the sclera.
Action
Intorts (incyclotorsion), depresses, and abducts the eyeball; acts as the primary depressor of the eye when the globe is adducted.
Innervation
Trochlear nerve (cranial nerve IV).
Clinical notes
Trochlear nerve palsy (CN IV palsy) manifests as vertical and torsional diplopia, especially on reading or descending stairs, with patients tilting their head toward the opposite shoulder to alleviate diplopia (Bielschowsky sign).
Related structures
Educational references
FAQ
What is the role of the Superior Oblique (Left)?
The superior oblique is a fusiform muscle located in the upper medial part of the orbit. Arising from the sphenoid body, it runs anteriorly along the superomedial wall, terminates in a slender tendon that loops through the fibrocartilaginous trochlea, and then reflects posterolaterally beneath the superior rectus to insert into the posterolateral sclera. It is the longest extraocular muscle.
Why is the Superior Oblique (Left) clinically important?
Trochlear nerve palsy (CN IV palsy) manifests as vertical and torsional diplopia, especially on reading or descending stairs, with patients tilting their head toward the opposite shoulder to alleviate diplopia (Bielschowsky sign).
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details