Muscles of the eye - extraocular muscles and movements

[@AkingAquila]

This video is highly underrated! I could not for the life of me understand why the Superior oblique caused depression (and the converse, why the Inferior oblique caused elevation). I had watched several videos (KenHub and AnatomyZone) and they all just stated the actions of the muscles. Dr. Webster here was the only one who took the time to explain the axes of the eye, and how the various muscles crossing those axes result in their primary and secondary eye movements. BTW the answer to my question was that the Superior oblique actually runs anterior to posterior, so when it contracts, it pulls the anterior portion of the eye downwards! Hence the depression. I'm sure I'm not the only one who had that problem haha. Dr. Webster, you've got yourself an extra subscriber! Thanks for the great, hands-on explanation!

[@olivia31192]

So so true! Thanks so much Dr Webster!

[@AliAhmed-rr6ny]

exactly what happened with me

[@cowsmoon8686]

I totally understand everything as to what you had just said there...

[@expectopeetrrronium7349]

still didnot understand why sup oblique cause depression. pls explain

[@hiefia8568]

@@expectopeetrrronium7349 muscles have an origin point and an insertion. When they contract, they move the organ they are attached to toward the direction of their origin. The superior oblique muscle moves from the back of the orbit( posteriorly) along the side( medially) until it gets to the trochlea where it switches direction from medially to laterally. From here it moves from front to back( anterior to position). The ability of the superior oblique to depress the eye occurs when the eye is moved medially. I think this eliminates the contribution of the medial to lateral angulation of the muscle. Hence your eye is stuck with only the influence of the anterior to posterior angulation. And since the muscle will pull towards the origin and since the anterior has become the "origin" in a sense, your eye will move from back to front. But remember that the eye is now adducted ( medial ) so your final eye direction will be down toward the side( ie inferomedially).

[@valentinemcdermott]

6:50-7:30 deals with the anatomy of the superior oblique and is an excellent explanation of why the SO can cause depression of the eye.

[@indianindian7757]

Tysm for this

[@kathmandunepal9547]

OH MY GOD! Its been 5 YEARS!! Since 5 years i was soooo confused about how superior oblique could cause the eye to look down when it lies upward! I checked for videos back in 2014, didn't find any! Finally you've made that point super clear!

[@gopalreddy7582]

I still didn’t get it can u explain me pls

[@mcmoodoo]

Incredible clarity! Super comprehensive! 24 minutes of pure ocular value!

[@lexihernandez4191]

Ive been watching your videos for couple months now, and I just wanted to say your passion for anatomy is inspiring. Thank you, for teaching and possibly never even being able to see the fruits from which the seeds you have planted.

[@andreiacastanheiradasilva8287]

While it's easy to just memorize the actions, it's hard to really understand it deeply - thank you so much for not being concise and really care to explain the logic behind it all! 👏 Your video was, amongst all the other videos I've watched and all the descriptions I've read in textbooks, what helped me most! I'm sure your channel will be accompanying me through the rest of med' school 🤗🙏

[@ShreyaRajgopal]

Amazing clarity. Also, you look very much like Dr. House.

[@RohanBanerjee0]

Whenever I'm stuck with some anatomical problem, I know there's one man I can look up to for solution, and that is Dr Sam Webster. You truly are a great teacher sir. Thank you very very much for posting these gems.

[@souviksikdar3180]

Tomar pod marboh

[@ruby-pm8zw]

first of all- beautiful eyes, secondly thank you I will be spending NYE with you- so happy New year to you and to every student on this platform

[@rohangandhi28]

You are amazing man, I mean I was struggling to understand the “complex” movements of SR, IR, and SO,IO. Thanks for explaining!!

[@Ayush_l_Singh]

After reading out most of those beautiful comments people have posted for you Sir dr. Sam,nothing is left to say for me. But just to say thank you so so very much sir for making this subject super interesting just the way you present every bit of it. Mannn, I'm just speechless. hats off to you and your efforts.❤ Edit : and yeah I'm very well keeping up my promise of commenting and givin' a thumbs up on every single video of yours present on this channel cause' there is no better way of givin' u a present as of now for ur efforts when we r living thousands of miles away unfortunately. 😅

[@irenacastle5482]

Best explanation I have found. Not even expensive anatomy books touch on this.

[@danielpa8644]

Excellent lecture, especially the part where the bony cavity AP axis that holds the eyeball and muscles is actually laterally deviated. So when pupils appear to be in the center of the eyeball the pupils are actually medial to the bony AP axis. This is why the eye muscles cannot work in isolation. Because the muscles are attached past the vertical and horizontal equators the eyeball, contractions of the eye muscle cause the eyeball to move along multiple planes. This is why the inferior oblique muscle pulls the eyeball up and out. The name of the muscle is just its location not its function. How this was engineered is incredible.

[@Mariam_oluwaseyi_]

Finally! Whew. Your explanation is so explicit I'm so grateful

[@DrCarlosAndresGarcia]

This is the best video i’ve seen of the movements of the eye🎯. I’ll upload mine version in spanish this weekend!

[@Jamjam107james]

good stuff

[@hebaelnabawy8871]

I have watched several videos and didn't want to watch this since it's longer but seriously this is the best and I've wasted more time by watching the other videos wish I've watched this earlier. Thank you wish you all the best doctor :D

[@nsglaasakr8217]

I have been searching for a compelling explanation for the written actions of the extra ocular muscles and u r the best....ty so much

[@toniencheff4046]

Happy New Year, Sam to you and your family. I hope you all had a great Christmas. I saw the video with you getting the Christmas tree with your wife. I am very grateful for your excellent videos. Thank you from the bottom of my heart.

[@muskangaba4341]

Thank you for giving everyone an access to quality medical education ❤️

[@hilal5159]

omg what a perfect teacher, cause of the pandemy I'cant go to university and can't do our lab lessons conclusion of it I can't picture these anatomic structure in my head but this video helps so much. thanks a lot

[@missunknownps3]

Superior oblique causes intorsion Inferior oblique causes extorsion When they work together they cause Abduction Superior oblique pulls eye down Inferior oblique pulls eye up THANK YOU FOR EXPLAINING THIS IVE BEEN LOOKING FOR A GOOD EXPLANATION!

[@mariashieladolosa8239]

I need to watch this video. Thanks to you Sir. I like your accent, it's very nice to hear.

[@jamescartwright387]

I've lived for 25 years without knowing that my eyes rotate...mind blown

[@nnassa4489]

Must’ve never rolled ur eyes at someone

[@IldaBegic-wz8oe]

Thank you so much! I`ve been looking for this kind of explanation forever. You saved me 🥰

[@corn1078]

This is cool, helps me understand last week’s strabismus surgery a bit better :)

[@rbg7408]

When fun and wisdom goes together... thank you sir!

[@喵シーアー]

Thank you very much for this video! I had so much doubt studying the extraocular muscles movements, and was at the same time wondering why everything goes in the opposite direction in the H test! I agree with you that these take a bit studying, but it’s now much more better after your explanation. Thanks again!!

[@amulcool7229]

Thank u so much sir❤️❤️❤️.... Literally searched every other video but never understood the secondary and tertiary actions of oblique muscle...

[@debarghapati8917]

I have no words to thank you.

[@s.a5590]

I am so bored for lockdown so I here just to learn something new haha

[@nataliebray]

This video helped me understand the extrinsic eye muscles for my anatomy practical exam. Thank you so much!

[@medicine4094]

i really ask god to bless u every day

[@rajatsingh24k]

The insertion points and the fact that the axis of the eyeball in the normal physiological setting (baseline) is different from the axis of the orbit are key. Watched 4 other videos before this one and they were all sh**. This video is the only one so far that made this concept clear. What an amazing teacher. Med schools should just show Dr. Webster's videos for anatomy and save everyone a ton of time!

[@watermelonsugar_1535]

Thankyou so much, my confusion about intorsion and extorsion is resolved. 😊

[@ቡጡቃ]

Excellent explanation, Dr.! I've become your humble subscriber😊 Thank you!!!

[@palashbinayake6904]

Thank you sir, this video made it easy to visualise and imagine how those muscles work , excellent job.

[@ramahmardini222]

the best anatomist evvver

[@kareenabudhrani9261]

This is sooooo gud ... SO was irritating me and I got it now.

[@rafal3941]

Thank youuuu really I mean it you’re pretty good ❤ الله يوفقك

[@rezarezanaghibi]

Wow terribly informative 😮

[@Disha-k4f]

You've made this so interesting. Thank you!

[@VMGChannel]

Really helpful. Thanks

[@Knucklesdeadlypunch]

Thank you so much Dr. For sharing your knowledge now I have a better understanding of eye movement and I can finally help my anxiety bc I have a better understanding. Again thank you. Be blessed 🙏🏾🙏🏾

[@rafiatajani1712]

How would it cure your anxiety tho

[@Chrysolite-kn3mz]

Thank you so much Dr Webster; you explained all so well, especially the reasons behind the actions of each muscle, which all kind of depend upon the axis they lie upon.. as I was watching your video, I came to a realization how unique and amazing God's creation are.. thank you.

[@ruthdominguez1542]

Watching your videos helps me understand the concepts. Thank you!!!

[@tommybryant4985]

Wonderfully informative 🫶

[@عليسلامخزعل]

Amazing tutorial

[@cousium]

Hey Sam, i'm from france, it's not so easy to listen english (when you don't practice it enough ahaha) but your video is very helpfull and you just clear my mind about this subject ! Hope to see you making more video about eyes. (for my knowledge and my english ahaha)

[@SamWebster]

Thanks - if I tried to do it in French it would be terrible!

[@lenaatyat5186]

You’re the best ❤❤❤

[@kikibear12146]

Well done video!!!

[@amanagarwal2746]

Superbbb... Sir And the thing you said at the end was just amazing

[@jibansharma4227]

It was damn impressive. made it so easier to understand. big thanks Sam. Best in the internet for extraocular muscles.

[@kalpanayadav2836]

Thank you for making it easier to understand 😊

[@atomoyoga]

Great video! Just pointing that the explanation of why we move the eyes does not explain why we move the eyes when we sleep. Looking is not the same than seeing

[@PatDotto]

Amazing explanation!! Tks ❤️

[@juliethomas8401]

Beautifully explained !!

[@gaynorankamah7381]

Great video, thank you.

[@doctora.s3461]

That waaaas perfeeeeect .. thaaaanks alooooot, your explination was really beautiful, i just remembered the greatness of god, he is reaally powerful.. i loved him more because he give us such a great eye, more powerful than any camera. Thanks alot again and again

[@MokieHotSquad]

Allah smiles at our salvation brother

[@MustafaAli-ug3qw]

Brilliant, thank you so much.

[@WmTyndale]

Very nice. I do not believe that science understands how the eye works at the computer level. Stimulation to output, mapped out like the circuits of a computer chip. It is only understood crudely on the basis of Newtonian Optics. I say this because a certain Dr. Bates linked the misuse of these muscles to the development of refractive errors. My feeling is that cramping, spasms and other muscular stresses brought on by long periods of optical duress weakens the organ. Glasses finish the job as does any intervention on the basis of incomplete information. Using these insights many individuals including myself have been able to partially or completely reverse myopia. Muscular Rehabilitation is the key.

[@pc_opinions]

An excellent video on eye movements. Great job!

[@mussahaji905]

The precision of how human being has been created is sufficient to conclude that there is a creator

[@boredtimes953]

What if each muscle was created by a different god?

[@qudsiashakeel7920]

THIS WAS AWESOMEEEE!! thank you Dr.Webster

[@sumitkumarsah5161]

🔥🔥 Love from Nepal

[@mzml4696]

Even a non anatomist like me can make sense out of it. Nice and interesting Sam . :)

[@mlemay2486]

Other than the excellent explanations.. you make me laugh! I love your humour :)

[@kishorekumarbangi512]

Nice job.

[@priyankarane6554]

Just love you for this one 😊🤗 I like that color of your eyes.. Seriously 😍😘

[@countto5591]

Very helpfull...man..really thank you

[@YH-nr7my]

thank you so much! it was the most helpful video :)

[@rafiatajani1712]

His eyes are so pretty 🥺

[@omarisam3650]

excellent video!! thank you

[@gavinpersaud4243]

excellent video and good commentary. Thanks mate

[@puneetkantiwal8097]

Awesome video man! U cleared all my doubt, great job! Thanks a lot

[@sibunal7410]

Why so good 😭

[@clearwavepro100]

Wonderful thank you!

[@szehonyu7325]

That's so useful! Thanks man!

[@duocphamtruongtho4462]

Thanks very much!

[@shavisingh6393]

Thank u soo much sir for interesting demo nd stressing ur eye . Great work

[@martynasvenckus423]

Never thought I would learn from Dr. House himself

[@Saidoromo2024]

Informative 👊

[@محمدالدوسري-ق1ذ7ر]

U are really amazing!

[@keertidpai7939]

Thank you sooooooooooooooooooo much

[@igorlimamaldonado725]

Excellent.

[@suyukthaseelam4297]

Such beautiful eyes..

[@fatimaa-q6f]

Amazing!

[@yixuan_yx]

Great explanation. Thank you so much!

[@ngocminh8068]

Thank you again

[@Soaresbrook]

Excellent video, man. i could be sure i've got trochlear palsy after your explanation of eye rotation, It keeps the horizon in the healthy eye, but it doesn't in affected eye.

[@zeelpatel8049]

Very well explained.Thanks.

[@elchin571]

thank You for great explanation!

[@charlesdartagnan8788]

I'm slightly confused by how the superior and inferior rectus muscles cause adduction of the globe when they work together. Is it because they both insert into the medial hemisphere of the globe?

[@saddikhaddad1586]

Thank you Sir!

[@dr.zaynab4450]

Ilove u llove lesson to your lecture ..really thanx to you ♥

[@shwanmussa674]

Dr. zaynab Hello Miss Zaynab from where you are ?

[@clarisalolita7d]

Thank youuu for the great explanation

[@h0m0.sapien]

Simply amazing!!

[@anfaljaryan4268]

you are amazing

[@pieterwets614]

20:25 "When we're looking medially, the only muscle that can cause us to look up - to elevate the gaze - is the superior oblique". Even if you meant the inferior oblique instead, I still don't quite understand why the superior rectus doesn't work efficiently when the eyeball is in an adducted position. Also, you're an amazing teacher and I wish you all the best.

[@SamWebster]

Dammit - I can't believe I made that mistake. This week's video will cover this again with cranial nerves and movements of the eyeball. When the eyeball is adducted the attachments of the inferior and superior rectus muscles are pushed out laterally. When they contract they want to pull the eye ball back to a neutral position and elevate/depress the eyeball. Not sure if that idea helps!

[@pieterwets614]

It does! Thank you and I'm looking forward to the next video.

[@dranandvarunachari]

He is amazing ❤❤

[@narasimha7870]

Thank you for saying why adduction by RECTI!!!!!