The Muscle that Unlocks the Knee: Screw Home Mechanism Explained | Corporis

[@ianjohnson4987]

78 year old retired doctor studying foot health here. What a brilliant video. Thank you. Liked and subscribed

[@jarelmarcelin4985]

I am a biomedical engineering student who just took anatomy and physiology this past summer! I am considering of double majoring in biomedical engineering and athletic training. Your videos are very detailed and interactive. I definitely have used them to help me through the multiple systems in the human body!

[@truthbetold711]

What can you recommend for a locked knee due to a torn meniscus?

[@thabomwanandimai9936]

Hi Jarel, did you take up the double major? I'm a PT student, biomedical engineering sounds interesting

[@pghparkins]

I am a middle-aged nerd who loves learning. I know the body "just knows" how to move proper muscles in all kinds of ways, but for some reason that little muscle that twists the knee in the right way depending on whether we are sitting or standing without us ever having to think about it was really fascinating.

[@Corporis]

I thought so too :) It's one of those cool consequences of bipedalism

[@NEETmedicalGK]

@@Corporis Subscribe and Thanks Sir.

[@1unsung971]

The Nervous system is the system that "just knows." Muscles are merely the slaves of the CNS.

You are not a nerd but a wise guy

[@dt5092]

I’m an occupational health researcher looking at repetitive stress injuries. Your videos have been so helpful in deciphering physical therapy notes! Absolute life saver!

[@Bdubtheblack]

I'm an SPT who has an exam tomorrow over the lower extremity. You're a godsend!

[@nikevisor54]

Watching this while rehabbing a knee injury👌

[@emil1063]

Same :/

[@Corporis]

A new meaning to the phrase "My body is ready"

[@PaulSmith-pr7pv]

I’m also rehabbing an injury but I also love this content. I don’t work in the medical field but I’d love to change jobs one day.

[@spectraanon]

Same buddy

[@saraomar8621]

I wanna know how can I use the practically in rehabilitation ? I am frankly fascinated but then what? Tell meeeeeeeeeeee how can i use that greatnesssss

[@camver100]

Oh man this is going to be a huge channel , those animations and model explanations and well articulated definitions are unlike anything I’ve seen

[@orungbejatoluwani7363]

Finally found a video the explains knee locking properly

[@CrochetIsLife54]

I’m nearly 70 and fractured my patella. I tripped and fell onto the knee, which was in multiple pieces. I’m a reasonably decent layperson when it comes to scientific jargon, but this is my first time learning about bones, tendons, and a rather complicated joint. I thought my PT will go better if I learn how the knee works and understand better how the exercises improve function. Thanks for providing educational videos.

[@snorlax9258]

how are you can you bend it already?

[@DJ-bo4pz]

Wow,....I didn't know a channel like this existed. I injured my knee, and I was trying to understand how knee works, and what part of it could I have hurt. My guess is that I have sprained my popliteus muscle because my knee hurts when I stand up from a sitting position. Once I am standing, it barely hurts (which is when the popliteus is mostly contracted and not under tensile load). I might be wrong, I am not a doctor but your video is a great help for us non-medicos to understand basic human anatomy in context of daily activities that our schools should have taught us. May you get 10 million subscribers.

[@tarrySubstance]

I am an Information Technology student who is also a fan of learning anatomy and physiology. The human body is a work of art.

[@1unsung971]

A work of evolution

[@pierobuhytron3670]

Dude, this is by far the best Anatomy video I've ever seen. Great teaching methodology

[@AlexisAcosta-wr6kf]

Good stuff man you actually tap into how a person actually learns not just coveying information 👌

[@Corporis]

Thank you! I take pride in my teaching style

[@OliviaFlores-m1]

THANK YOU!!! I could not understand this mechanism whatsoever until after watching this video

[@sidrens5292]

Excellent presentation!!! I am a Sports Therapy student at University in UK. These videos are some of the best around.

[@gracemitchell9191]

Thank you, I am a biomechanics instructor and this is the only good video on this topic on KZbin!

[@KatherineCarrier]

Thanks! Hey! I’m a yoga teacher and this has made me an anatomy nerd :) this is so helpful!

[@bestonemusic]

Do yogis eat a lot of yogurt?

[@marka.schlueter9918]

Just found this and it is a great explanation. I went to my PT doc and was having issues with my knee. With my legs hanging off the table he said I have an issue with the "screw home mechanism". The what??? It took a lot of time, but he kept pulling down and slightly turning my lower leg when I finally heard or felt a tiny "pop". Did he release something? Not sure of the jargon but after several more visits my leg felt normal again. He said that in his 15 years of teaching and attending to clients, it's the first one he's ever seen. We surmised that it probably occurred in Jiu Jitsu class. Thanks for the clear illustration of the SHM.

[@nicholashockings9584]

Hello Patrick. I have to say, I've only just discovered your content, but I absolutely love it. I've already signed up to your Patreon and I sincerely you hope you continue making more science education videos. I'm a high school science teacher and former medical research assistant. Like yourself, I'm passionate about teaching science as you are. I often create content for my students and I'm really interested in finding out how you make your videos. Tbh, I'd actually like my students to learn how to make similar videos through their own second hand research. Anyway, keep up the great work.

[@felixslytherin6567]

Your content is always on what i need the most Are you my guardian angle❤

[@ishaqureshi402]

Never been so concentrated on a video than this. You had me along every second and now that I understand it, it really is Mind-blowing. Thank You.

[@mikew370]

Thank you. I will be back. I had a tibia fibula break, with a tibial plateau fracture that has been screwed and plated and a single screw inserted down into the fibula from the top. Seeing how it all works has helped me understand why I am still struggling with some simple things like leg curls and sitting knee extensions. The plateau fracture tore the cartilage and it seems to have gone right through where the patella tendon is attached. I almost certainly snapped my pcl and definitely damaged my mcl. My lcl was fortunately still attached to the end of the fibula when they screwed it back on. This video has really helped me understand it. Thanks

[@yarenengin5630]

i ' m physical therapy student and i think i'm totally fall in love with this channel

[@claytonmagnuson1677]

I'm a PTA student, just learned about the screw home mechanism. I love your videos! You explain stuff really well and make it easy to comprehend.

[@cecilia5103]

I am massage therapy student and your videos are amazing!! The academy I attend reads from our book(s)...they don't really teach! Your videos have helped pull everything together for me and make more sense!! :) Thank you for creating!

[@aafreenimtiaz901]

I am a bachelor of physiotherapy student,i like ur way of talking ,ur teaching style , overall thumbs up 👍🫀🤗 appreciate ur efforts and the mankind to the 🌎

[@maxjordan2625]

Wow i learned so much! Thank you! Tore my lateral meniscus and got a stitch in it/got it trimmed and after 2 months I can't quite lockout my knee still and this helps me picture what's happening! I can extend it just maybe 1 degree past where the hamstrings relinquish control to the popliteus, or so it feels... Was a scary feeling but this explained it so perfectly.

[@xw591]

Wow! Definitely learned something. My knee is achy after a workout yesterday and this helps me make sense of who's on first.

[@shagungarg4091]

I am a physiotherapist student .For us, Its very important concept to understand and i already saw lots of vedios but i never get it before.Thanks to u, today i understand whole concept. Thanks sir

[@ravihls]

wow. great information i had a logitudinal tear in lateral menisci ahd the surgery for the same. but my knee was locked and cant extend that final few degrees. My physio did all she could but this is a new iformation that i can share with her - hope i will get a fully extended knee one day

[@patrickbianconi1817]

From another physio, great job and great explanation with this video on a complex topic

[@juliu45]

As a biomechanics teacher, I can say that this is a great biomechanics class !! 🦾 I will redirect my students right here

[@lesleysprake1045]

Wow that was fascinating ! It’s the only thing I’ve seen focusing on this little muscle ! I’m fascinated

[@KC-wm6tr]

2:36 cruciate ligament PCL tightens and helps glide tibia anterorly during extension ACL tightens and helps glide tibia posteriorly during flexion

[@KC-wm6tr]

3:52 popliteus: lateral meniscus --> medial posterior tibia for IR tibia (open chain) / ER femur (close chain)

[@arthur1010123]

Fantastic! I'm a physiotherapy student from the Netherlands, and this video is really helpful for my studies. Thanks a lot!

[@precisecovers2551]

MRI student! I've watched your videos before, I specifically remember your anatomy and physiology of the kidneys video, which helped a lot! Cheers!

[@chazmuska]

NASM certifed PT. Im fascinated learning everything about the human body. Its truly a work of art!

[@AkbotaZhailkhan]

first year med student here TT have exam tomorrow and got stuck on knee joint... thank you so much! really cleared up a lot of things for me

[@saamazul]

Thanks for your explanation, i'm currently studying for the NPTE and this video help me a lot.

[@gigihoo2978]

Finally 😩some one explain Screw home mechanism for me 🙏 Thanks!

[@AbigailSnyder-js2mc]

In my last year of PT school, taking the boards soon, and this was helpful-thank you!

[@melissaadrian-w2j]

Great video and I am a SPT! Very well done and helpful for understanding difficult anatomy concepts! thank you!

[@MissDollyDimples]

I am a first year Physiotherapy student & I love your content! 🇬🇧

[@someonesson6222]

I'm a Physical therapist assistant at a hospital in Central Phoenix Az. Years ago I strained my left popliteal muscle, and I currently am having an issue with left popliteal muscle again. Thanks for the video!!

[@Corporis]

My pleasure! I actually used to work in a clinic in Phoenix as well during grad school!

[@henriettkoti7766]

I am a personal trainer, with ambitions to study sports rehabilitation and physiotherapy one day, and your anatomy videos are really inspiring me to pursue these dreams👣 Your videos are truly amazing, I recommend it every time when a colleague or another PT student asks my advice for the best anatomy YT channel. Keep going Patrick, your videos make a huge impact ❤️

[@itszach930]

Thankyou! By far the best video explaining this!

[@anupkumar5662]

This was amazing . I am a strength coach who has to deal with athletes and general clientele of varying sports, levels , abilities and injury histories. As part of my own learning and growth I made it a point to keep exploring varying fields of learning for better performance. Anatomy is one of my weakest areas ... I've always found it complexly written and explained. I did not make much headway for these reasons into the depths of joint mechanics. This to date is by far the greatest explanation of some of the knee joint characteristics that I have ever come across. Thank you for this. Keep up the good work. SUBSCRIBED !!!!!!

[@1unsung971]

How can you be a strength coach if your knowledge of anatomy is weak???? You should immediately refund all your clients to date. That's immoral and unethical

[@agnes4901]

i'm a pt trying to learn the terms in corrective exercise course, thanks for the video, it's quite helpful! 🙂

[@ShauntelleCannon]

Extremely helpful video. Thanks so much! Right when I needed it as an audiologist studying for a biomechanics quiz and no background of anatomy outside of the ear.

[@PFMediaServices]

I am just a gal on the internet who loves learning things and everything in this video was new to me, except the locking mechanism seemed incredibly familiar. Because after falling down a rabbit hole about amputation and prosthetics, I recognize it as a "feature" that's becoming available in newer leg prostheses! If I recall, for a more normal gait, simpler ones require a sort of kick forward with every step that takes some getting used to, (apparently going down his and stairs is quite an ordeal to start with) and now there are models that can semi-lock with a button or switch toggle for walking vs. standing vs. sitting (some are toggled with a set number of toe taps, which is very cool and fast less intrusive) and higher-end models have sensors to enable/disable this automatically? I think? Anyway, what I'm saying is how incredible our bodies are, just all on their own without having to think about it, and how challenging it is to reproduce many of the little aspects we take for granted. Wow.

[@ruturaval1829]

I am a first year physiotherapy student and this video is so useful for my anatomy exams.

[@Jazoolee]

Just a regular athletic/engineering dude who is interested in the anatomy of the human body😍 Love your videos man!

[@beanface8586]

As a student RMT, this video was very helpful in explaining this mechanism in a simple way. Thank you so much!

[@tehreemfatima8067]

Thanks ....you make it easier to understand

[@MAmeer-fr2hp]

I'm a medical student and i really love your content. Keep up the great work!

[@autisticcormorant6881]

oh man if only there was a video for each muscle anatomy would be a breeze. Great video thanks a lot! Hopefully m. popliteus comes up on the exam

[@nordicathletics]

Amazing quality video

[@tomtenthij5676]

Thank you SO much! this video was very helpful!! :D

[@crystalfavorito7820]

At 2:36, isn't this reversed? I thought the ACL tightens during extension, and the PCL tightens during flexion

[@Waybear]

I passed my MBLEx thanks to your channel. Thank you so much!! Keep up the great work!!

[@Corporis]

I appreciate the kind words, congratulations!

[@drSJV]

Thank you, such an amazing video!

[@pandoraefretum]

Good clip ; good question. I am a 59 year old violinist (now teaching) who suffered a major stroke 1.5 years ago

[@nutritional_yeet]

OTS here, this vid helped a lot in understanding what is actually going on here

[@buthkoludom8th758]

Great video!

[@kevjumbaz]

Screw home mechanism = ER of the tibia during terminal knee extension to provide stability. Popliteus helps to unlock screw home mechanism stability: 1. CKC = ER femur on tibia 2. OKC = IR tibia on femur

[@pawesuliga8815]

I really like all of your work! Currently I am working on pathological defects in pig's muscles. I am focusing on M.Semimebranosus and M.Adductor. Here the importance comes with their function but I also compare pigs that have a different level of movement availability ( free-roaming vs conventionally kept). Thank you for your informative videos!

[@drdollysl1525]

Hi, Nice information

[@abdulkadir8358]

Thank you so much

[@leenalhaj.]

2:36 I think u said the opposite regards to ACL/PCL function

[@Corporis]

Before researching for this video, I thought it was like that too. But according to Physiopedia, it's the claim I made in this video: *During knee extension, tibia rolls anteriorly, elongating the PCL and the PCL’s pull on tibia, causes it to glide anteriorly. During knee flexion tibia rolls posteriorly, elongating the ACL and it is the ACL’s pull on tibia, that causes it to glide posteriorly.* www.physio-pedia.com/Screw_Home_Mechanism_of_The_Knee_Joint

[@leenalhaj.]

@@Corporis thanks

[@rpc1605]

Very technical, but also very interesting. I was in a car accident and was thrown forward on the tarmac. My right knee took a hard knock while rolling to a standstill. When I tried to stand up, my knee just folded under me. It wouldn't take any weight. It swelled profusely.

[@thomasdayooshadogan1045]

Thanks Corporis, u are very nice.

[@bildadolemukol-dt4ym]

MBChB Level I here, found the video quite enlightening

[@dietformea]

Excellent

[@justaguy328]

That's absolutely astonishing engineering. Crazy that people think an unguided process could produce such a thing. We are wonderfully made!

[@1unsung971]

Evolution is random mutation. You need to understand that to understand human function and physiology

[@xw591]

Yeah, "made." Becayse tge homosapiens that couldn't walk didn't reproduce. Unfortunately for you, the ones that couldn't think DID reproduce, and here you are.

[@myfeliscatus]

Well done.

[@ROMANEMPIRE69]

I have right internal knee pain. Been seeing a chiro and doing pt. Still pain. Gotta get an mri to rule out any tears or other damages

[@glennshibu5776]

much love from a struggling physio student

[@chpapermagic1370]

Thank you for the explanation, fo me i have a popliteous pain, it is difficult for me to band my right knee, and am a basketball Player.

[@user-rp4pb3oo5y]

Thank you for your very helpful breakdown of the screw home mechanism! Since the sartorius helps to medially rotate the tibia when the knee is in a flexed position, does the sartorius also play a role in bringing the knee out of full extension? Otherwise, when else does the medial rotation of the knee by the sartorius take place?

[@angiegoode9152]

Hi, just have a question: how does the ACL and PCL "tighten" if they do not have contractile tissue?

[@aysugano1]

I absolutely loved this explanation. I am a dance science ballet coach. I wanted to ask you something in a DM if we could. Thanks so much!

[@jhmho]

thanks for the explaination! i am a physiotherapy year one student

[@Corporis]

Happy to help! Best of luck in your studies

[@jerrysegal2903]

found you by accident but great stuff. A question-the screw home mechanism is the reason to not fully lockout on a leg extension machine since it forces the condyles to grate against each other?

[@grampafitness9732]

Personal trainer here ... one who got physically active in my late forties because I have pre-arthritic deterioration in the meniscus of one knee. Had to learn some basic anatomy and kinesiology for my certification, picking up more as I go along because it helps me stay within my scope of practice as a non-expert but lets me tell clients "this sounds like it might be X, but remember my training has VERY serious limits: please see a physical therapist or doctor to find out what's actually happening, and get advice on what I should or shouldn't encourage you to do." At least two of my clients have knee issues of their own. The more I know, the more I hope to be able to help them prevent further issues, without adding to their woes by suggesting things that would be bad for them.

[@1unsung971]

You should know this stuff already!!!!!! Go to Physiotutors. A little knowledge is enough to hurt people.

[@gasdive]

I'm an ecologist, but I'm fascinated by the evolution of this structure. Our closest relatives, chimps and bonobos, don't have it, so it's a very recent development.

[@samalaanandkumar4590]

Superb👍

[@emangamal4068]

Helpful

[@doaatarek5662]

Great !👏

[@Fractal55]

thank you :)

[@hangukhiphop]

The screw home mechanism is nice but I'm much more fascinated by the "screw you guys I'm going home" mechanism

[@Corporis]

I LOL'd at this

[@StephenSambo-j9q]

Hi sir..... I have a little question about my knee which constantly bother me...... OK here it is........ I did an X-ray of my knee today, which I got the injury from playing football (armature). The doctor said dat they hav to run a surgery which that I have a bone growth..... Am scared of loosing my leg.... Can't there be anyway out? 🙏😭

[@aheartofworship27]

My surgeon said I needed to liste loosen the popleteus tendon. It hurts though. Any good videos on this?

[@PeterUpton-pk7jw]

Hello - I am a gardener in the west of Scotland, retraining in foot health. Leg and knee anatomy is part of my course. I enjoyed this video, but your delivery is rather fast. If you could slow down and give a few pauses to allow information to sink in, that would be a real help! I'll be back for more, though. Thank you!

[@rph_redacted]

I am a pharmacist who loves learning about anatomy, physiology, kinesiology and fitness in general.

[@darlenawade-williams579]

Hi, my name is Darlene, and my right knee has been locked straight for about eight years. I’ve seen an Orthopedic surgeon for years. However, he explained that it would not have much difference if I underwent a knee replacement surgery. He claims I wouldn’t have too much more movement in my knee than I have now. Is there another option for me to get my knee unlocked? Most of the time, there’s no pain. Thank you for whatever advice you can offer me.😊

[@felixslytherin6567]

Hey But according to pubmed and grays anatomy in flexion pcl is taut Can you check this up

[@cpt.battlecock5264]

Wouldnt locking of the knee not occur because of an internal rotation, Like the medial condyle twists medially backwards, And the unlocking be done by external rotation with the lateral condyle pulling backwards then medially?

[@Blafee1]

Very didadits. 👏🏻👏🏻

[@AliBasheer-t9x]

Greate explanation but why that speed of taking

[@JoeMoran1968]

stroke survivor my though i have control i di have knee pain what can i do to relieve the pain/