One thing I forgot to mention is that the blade can get quite hot from friction. Another reason not to try this at home! The sponsor is Henson Shaving: Get 100 free blades here: hensonshaving.com/stevemould when you buy a Henson razor with code stevemould
When I was a kid the doctor said I shouldn't worry because the saw doesn't cut trough skin... I still have the scar from the burning it did on my arm though.
@@astropgn Me too. My scars are 30yrs old and my cast was made of the catalyzed fiberglas instead of plaster of paris. at least it also cauterized the wound it made but it also pushed the fiberglas dust into it. was crazy itchy for longer than I had to wear the post cast removal wrist brace.
I only had a cast once when I was like 8 or so years old, and I was terrified at the saw being used once it was healed, and thought for the longest time that the doctors were just THAT precise and skilled with the saw xD
I also had a cast (two actually, both ankles as my Achilles tendons were not growing fast enough), when it came time to cut the nurse asked me if I was afraid, and when I reluctantly nodded my head she held the thing to her arm and let me watch how it just tickled.
@@MrRandoOnly if the doctor moves the saw too fast. Human skin is pretty elastic, but if one moves the saw too fast, the greater pull of the saw teeth overcomes the elasticity of the skin.
My first job was with prosthetic limbs, we made a lot of casts, most people almost had a heart attack when I pulled out that baby, was really hard to convince them it was safe. Neve knew exactly why it was safe, thank you Steve for that!
...Why do they have people operating those things without telling them how they operate lol. It's not that complicated... tl;dr "It just twists back and forth and the actual disc isn't that sharp, so all it does is scrape plaster and soft stuff like skin isn't going to get cut." This would also hopefully prevent the issue in another comment where some medical practitioner was running the thing back and forth along the cast so fast, that it actually caused skin scrapes ._.
This made me remember when I had my cast removed from my leg when I was a kid and was terrified of the saw and the nurse taking the cast off took the saw and pushed it right up against her own arm to show me that there was no risk of harm. It's something that immediately put me at ease and I let her continue without even so much as a flinch. I hadn't thought of that until this video. Thank you for reminding me of what looking back is a really fold memory.
You were lucky. As a 6 or 7 year old who broke my leg, the person who took the cast off seemed to enjoy my state of near panic as he held up the saw and started to go to town. Maybe I got a sucker out of the deal!
I saw a nurse do that the first time I saw a saw (🥴) and I think it's probably something that happens literally every time the saw comes out of the cupboard.
Same. I was 5 yo. Helping my dad trim a tree by carrying the branches away. Tripped and broke my arm by falling from my own height. Doctors discovered I had brittle bones then. When I took off the cast, nurse saw my eyes widen. I didn't say a word and she said whyle pressing the saw to her hand "Don't worry. It doesn't hurt. See?". I broke that same arm again the day I took off the cast riding a bike LOL. Wasn't scared of the saw the second time.
@@ThZuao I was afraid that story might continue along the lines "...the same day we continued trimming the tree and I demonstrated to my dad what the nurse had done by pressing the chainsaw to my hand saying, 'don't worry, it doesn't hurt'..."
I had a random doctor cut off my cast in under 3 minutes. He showed me and put that saw to himself before touching the cast. I trusted that doctor. Now I finally know the science behind that.
About 60 years ago I had a little mishap resulting in a lower arm cast. When I went in to have it removed the doctor came in, and without saying much, turned on what looked like a rotary saw with the blade spinning and pushed it toward the cast on my arm. Before he contacted the cast I had his wrist fully clamped in my good hand, thinking this maniac was going to slice my arm with his crazy saw. The doctor's reactions were astonishment, then anger, then he laughed and put the saw on his own arm to demonstrate how it worked. So we both got educated; I learned about oscillating saws and he learned that patients may need to understand what he is about to do to them.
Incredible story. While I would hope this would be less common today than 60 years ago, it's funny to think that doctors would go straight into some sort of procedure (since they're the trained expert) without explanation, which would look like attempted disfigurement to most people. I had my first cast at 11 and was very inquisitive, asked about every step and just really wanted to know what was going on (really more from curiosity than a focus on my wellbeing). First time a cast was taken off, I don't remember being scared of the saw, but thinking "Either this is going to hurt, they're very skilled with a spinning saw, or there's something I don't know". I just asked how it worked and if it would hurt because I wanted to know, but if I didn't have that experience until I was an adult, I would absolutely have gotten defensive before the saw could take my limb.
@@Faustvonholle My experience of most doctors today is consistent with the story, we the patients don't need to know anything, they will do onto us as they think is best.
I had several fractures as a child and the man in the hospital who cut the casts of was super friendly. It looked like a really fun place to work and they were all jolly in that department. He always demonstrated the tool on his own arm to reassure the terrified children.
I have to say, I really appreciate that you took the time to explain _why_ trying this for yourself is dangerous and _how_ it could get you hurt, rather than just giving a boilerplate "Don't try this at home".
Yeah but don't they make those oscillating tools for cutting tile? Pretty sure he said Dremels were out, but as long as the tool oscillates you're good.
I remember being terrified of having my cast being cut off and the doctor just ran it across his arm while it was on and I was like “…oh” and I was fine. Honestly props to that doctor he must have had so many terrified kids coming in
Well in my country people are poor and we are like 20 years behind in termsn of technology so we don't have saws like that. And I've had a broken foot and what they do is they use a regular saw (I assume), because they insert a metal shin under the cast where they will cut and so if they break through the cast they will scrape the metal shin under it. The shin is thin however and I still feel like if it's somebody that is inskilled and moves slightly to the side outside of the metal shin area it can still cut into your body part :D
As an 11 year old in 1987 I vividly remember the doctor holding the case saw against his own arm to show me how it wouldn’t hurt me. Several casts and metal screws and plates from that broken arm I came to trust the cast saw and my doctor. Side note, I saw that same doctor more than 30 years after my broken arm and upon introducing myself as soon as he heard my name he immediately grabbed my left arm to inspect his work. He 110% remember me all those years later. Thank you Dr. Golden.
@@laurenanderson7330 of course, I was inside your whole peaking by the little whole I made. If you don't mind, next time pull down your pants more sensually, please
Hi Steve, minor correction from a UK Emergency Medicine Doctor. We still use plaster of paris as opposed to synthetic casts when you first break a bone. Plaster is better for the initial molding around the break. We also apply plaster to only one side of the cast, this is called a backslab. The soft side then allows for any swelling that occurs. This is usually then changed to a hard synthetic cast a few days later.
That's very interesting, thanks for explaining! I only had cast as a kid (so... definitely more than 15 years ago since the last one now), and it was always only plaster of Paris, so I wondered about the modern stuff :)
Hi, David. Thank you for your comment. Could I also humbly ask you: what is the purpose of the change from plaster to plastic if in few days plaster is already fully solidified?
@@NikolayBychkovRus I presume they have to redo the cast because swelling has gone down and it would be loose, and since there's no chance of it swelling up again you can use the faster cast (that sounds like a great trade name)
This is just a guess, but I would think the synthetic would be better in handling getting wet. I am not saying you would run water over it or soak it, but it could potentially handle getting wet (splashed not soaked) better than a plaster cast. Again, this is just a guess. I have never had a cast, so I have no personal experience with either.
Honestly, this is the first time I didn't completely dislike a "sponsor section" of a video. The information was - as always well presented, concise and relevant. Thank you so much for making those videos!
the doctor explained this to me when he cut the cast off, but I'm glad to see someone such as yourself explaining this for the people that don't know, and you did it in great detail as well.
Haven't had a cast yet, but in the field of automotive repair we use something similar, which also oscillates to cut out body panels for less heat buildup to avoid it from warping. However, it might actually get through skin at some point since it isn't designed for casts 😅
That comment about trying to find material properties of skin really hit home. I’m a bioengineer, and in college I first learned about regular materials, which are linear (behaves the same at different scales), homogeneous (all made of the same stuff), isotropic (same in all directions), and elastic (doesn’t lose energy when stretched), all very nice properties that make solving problems easy. Then I got to tissue mechanics and realized human bodies are none of those. In fact they’re so complicated the best we can do is ever-more-complex approximations that kiiiiinda work for very specific pieces and nothing else.
Also, it should be considered that skin (like many other biological tissues) is under tension on the body and this influences the wave propagation speed
This is exactly why the Dremel oscillating multi-tool, with an 80-grit sanding triangle pad, is great for exfoliating heels. The soft skin jiggles. The thick, dead, calloused skin isn’t as pliable, and hence it gets sanded off (slowly).
Fun Fact: If you have really dry skin, your skin loses some of that elastic pliability and become susceptible to being cut again. I remember learning this from another TH-cam comment section where a medical professional was sharing their experience doing demonstrations with the cast saw for kids, as a way to help them relax beforehand. However one day when they were preforming this demonstration on their hand like they normally would, their hand was somewhat more dry than normal, and they managed to actually cut themselves, much to the horror of the child they were attempting to calm down haha
For those without facial hair: Even though the differences in hair length on each side are difficult to notice on camera, the actual smoothness of the skin, as well as irritability after shaving, make a world of difference.
Regardless of brand, for pure clean face shaving safety razors are just better; the only reason to use a plastic razor is if you didn't know any better yet. If you were doing some more shaping and grooming of the facial hair, you'd have more room for electric razors.
I'm not sure if I was clear, English is not my native language. I was talking about a razor in the style of the old razors used by barbers, except with razor blades, so you don't have to deal with the sharpening.
@@jankoodziej877 I believe those are called straight razors, and yeah if you know how to use em they're deadly effective cause they cut real clean and the typically load half a blade so you can just keep the other half clean and wrapped up for the next time you need it
I remember having my cast removed and asking the lady in so much fear "that doesn’t cut through skin???" And she looked me straight in the eyes, turned the saw on and pressed her hand on it and I honestly started laughing with the nurse and my mother
Yep if they felt it and believe it they know they can press it on there skin and show you look it’s moving back and forth so little your skin moves with it. So it will only cut hard things on the surface.
Modern tools today I believe no matter the brand this tool won’t cut you and is it did you would have to really force it plus it wouldn’t even be mm deep it can hardly break the skin if you try and I’ve used many different brands from other people on the job. I do admit the best ones can hurt you a little faster but still really cannot hurt you. You won’t bleed at all for a minute then when you do it’s nothing and definitely less than you could ever do shaving.
Just breaks the skin slightly and is not dangerous. The attachment they use make it look rotary tho. It’s just for blade life and angles they can use still in it. They get better stuff than we do lol. But we can but similar also we can buy softer and give them a new edge with our drill attachment over and over until they become too short. You wouldn’t want these shavings in a human being I’m sure lol. But it’s same deal can’t break the skin and by the time it does you won’t know for minutes. Like when I guy is too rough with the clippers and later you get a couple little scratches. It’s about the same hard to really hurt anyone just good for hard objects. Maybe a shin bone but they gonna get away or kick you unless there tied well lol.
Cast saws CAN cut skin. If one were to move the saw along the surface of the skin, you would move it beyond the elastic limit of the skin. When removing casts the ortho tech or medical assistant (the doctor usually doesn't do this) presses the saw into the cast perpendicular to the skin, then withdraws it when they feel it break through the cast. After withdrawint the saw to the surface of the cast, it is then moved and pressed in again. The layer of padding under the cast is usually sufficient to protect the skin from the teeth and fron the het.
There is a similar oscillating tool meant for safely "buffing" your eyeball. Yes you read that right. I found that out the hard way. I got a shard of metal in my eye ( while wearing glasses AND safety glasses) and there was rust left just under the surface. They use a contraption to hold your lid open and buff away the spot without causing damage. They numb you with drops but you get to enjoy the experience while awake and watch it get closer..... Happy nightmares everyone.
A fun memory from when I was 5- -I was having a cast removed around my chest, and was, naturally, freaked out by the idea of a saw being brought near my body. The doctor, wanting to ease my panic, enlisted my mom to demonstrate how safe the saw would be, by showing it in use on her arm. Didn't spend anytime explaining the physics of this to her though, so my mom was the one panicking instead, though reluctantly trusting that the doctor wasn't about to slice her arm open. 😅
@1v966 Open heart surgery was what I was in for, though my wording there was a bit off- Was just a cast around my torso, not "full body". My apologies. Lol
@throwawaypt2throwawaypt2-xp8nx If I had to guess, to dispell any thought that he was somehow putting it close to him, without actually making skin contact. Otherwise, probably for comedic effect.
I am an orthopedic surgeon and cast saw injuries are quite common, even when an experienced person is using them. At my hospital there have been severe injuries. If you press the oscillating cast saw against a person's skin and then slide it, you will slice right through the skin. The blade can also get extremely hot if it is dull and can cause severe burns.
Thank you for your comment. I had injuries on my leg twice from having casts removed. It was like a burn from my thigh to my ankle and it hurt like hell while they were doing it, but the technicians scoffed at me and said it was all in my head. Now I know what it was - they were burning me with the saw because it wasn't sharp enough.
I got my cast cut off by an old cajun ortho when I was a kid. The dude told me 'if it cuts you, you can punch me'. Well I jumped when the blade went through the cast and it cut me. I didn't punch him though, he was a nice dude.
I don’t mean to sound too flippant, but it seems like you’re just describing Malpractice. They are operating the saw in a way it wasn’t intended to and causing harm because of it.
Do you have any idea just how therapeutic it was to watch this video? Growing up I was terribly afraid of breaking a bone and getting a cast, not because of the pain and immobility that'd be involved, but because a power saw would be used to remove the cast. The thought of the saw scared me more than anything. I only _now_ learned that all of that fear was for nothing. I feel like a weight has been lifted off of me, thanks to your video.
Well, fear no more! You can now enjoy the full experience in breaking a leg or two, getting a cast, have your friends and family leaving their signatures and drawings on it until the big final moment of removing it and you have a leg as good as new! Jk lol. It's such a liberating feeling when we discover these things that we've been afraid of and realize they weren't as scary as we thought. I'm happy for you, man. 🥳
yeah idk, I'm currently looking at the half-inch scar on my wrist from being injured via cast saw almost 10 years ago. I was in middle school, I vividly remember screaming at the sharp pain and the doctor looking at me like I was crazy. Beginning to wonder if they even had the right tool lmfao
This was possibly the most perfectly timed video recommendation of my life. I'm actually going to the doctor tomorrow where I'll very likely have the cast on my leg removed and I would have flipped out at what looks like a rotary saw being brandished by my leg. I am not a brave person lol Edit: They cut the cast with the exact same tool. The video did help a lot.
I was so afraid when my cast was removed. The assistant did say the saw does not cut my skin but I did not trust her as a kid. That thing looked dangerously like a mini circular saw. Showing me on her skin would probably have helped.
I’m loving all the comments of people sharing happy stories with doctors demonstrating the saw on themselves before using it on them. I never had a cast before, but as someone who is often terrified of medical equipment, that kind of understanding and demonstration is way more helpful than the doctor just apathetically saying ‘don’t worry’ and going for it when it’s clear the patient is confused and concerned.
They don't cut you, but if the cutter goes too slowly, the blade can get hot and burn you a bit. I remember a very slow-moving nurse trainee having to remove a cast from me, cutting super slowly, and the blade wicked hot from the friction and burned me. An experience ortho, however, removed one of my casts like he was opening a zipper.
Fun fact: 1976 a carpenter got his cast removed with this tool and seeing it's potential to reach and cut in difficult places, he sought to buy it from the doctor and took it to the construction site. That's how the cast saw became the oscillating multitool.
It's one thing to have them casually explain it in the doc's office, but to actually *see* how it works in slow motion and how that relates to direct contact with skin is incredibly useful in fully understanding just how safe it is. Doctor's should recommend this video to anyone worried about getting their casts cut off!
I use an oscillating cutting tool pretty much every day for remodeling work. It cuts effortlessly through drywall, wood, vinyl, etc. It's a classic move to stick it on our skin when we're working with a new guy and watch him freak out.
This is almost astoundingly coincidental to me: My son is having casts put on tomorrow for stretching his Achilles tendon and I was telling him about how they take casts off and , lo and behold, I get a ping for a suggestion to your video. Made a perfectly timed learning experience, for both of us. Keep em coming, you always find the most interesting things in the obvious that you typically don't think about
@@steinblitz1506 considering i often see notifications come hours after ive already watched the video it wanted to notify, that definitely sounds like the algorithm listening in
@@kirtil5177 that's my normal go-to conclusion, but it did just get released and I do have notifications on for this channel, so unfortunately I can't claim that this time. This time...
Just FYI: a plaster of paris cast is usually used on a recent fracture because it lends itself more easily to putting on a cast splint rather than a circular cast which allows for post-traumatic swelling. Synthetic casts are used for circular casts, which is shouldn't be put on any earlier than 5 days post-trauma.
0:47 That's not really true. My leg was put in a cast when I was 10. The nurse cut a groove down the front of the cast to make it easier to remove later. I screamed when it passed over my knee, but the tech insisted that the blade was harmless. Weeks later, when the cast was removed, we found a scar on my knee and a large patch of dried blood on the inside of the cast.
plaster casts are still used quite a lot, but for more serious injuries. they use chemical accelerators in it to make it set in an hour or so, its gets really quite hot as it does. only lesser injuries or later stages get the fiberglass ones. also you cant just get the speed of sound for your skin from the ripples since your not in the far field regime and the oscillations are quite clearly being powered. src: im a physicist who had a lot of casts...
Oscillations are always powered by something. Oscillations through the air are powered by your lungs when you speak. How fast those oscillations travel is the speed of sound through air. And by far field *region you're referring to the electromagnetic field around an object which would be relevant if we were talking about radio waves not sound waves. The speed of radio waves is entirely different from speed of the oscillation of compressive pressure (sound). Hope this clarifies things for you.
@@waxywabbit1247 this is wrong, and i dont think you understand. imagine this, you detonate a high explosive. the initial blast wave propagates at the speed of that explosive which is far higher than the speed of sound in air. once this hits air it will still go at that speed for some distance. this is called the near field, as you said this is also true for electromagnetic waves and is true of all waves. only after some distance will the blasts wave slow down to the speed of sound and propagate 'normally'. with powered i meant that the oscillations are forced at that frequency and do not yet go at the speed of sound for that medium.
This is some great content and in content marketing. I really liked the scientific approach with east to follow formulas from strength of materials, and the merger with of the topic with the sponsor of the video was flawless. I did not skip through and might consider giving a chance to the shaver.
When I was a kid, I got a cast and when I heard they'd use a saw to remove it, I was EXTREMELY worried for several days and nights until the moment actually came... and it was perfectly fine. That was maybe 35 years ago. Thank you for making this video 😁
If I were the doctor I'd put a big show and say: "Watch out, kid, this will cut off your arm if you ever so twitch even a hundredth of an inch!" And then approach the cast veeeery slowly. (" oДo)
@@hariman7727 the thing they forgot to mention is that as these blades lose their edge they generate more friction and get hot enough to burn through your skin... i've got scars as well and they've been there for the last 30 years
Hi Steve. I’m glad you made that comment about the heat because 40 years ago a doctor 3 nurses and my mother had to hold me down as they tried to convince me that one of those saws wasn’t able to cut me as they cut my plaster to loosen it from my arm. I still have the scar to this day which is about 60mm long. They may not be able to cut you but they can sure as s^*% burn you to the point that you think you’re being cut. My mother still feels guilty about not believing me when I was running around the room trying to escape these adults in my mind, hell bent on cutting through my arm! I can laugh about it today but not then.
I had almost exactly the same thing. Drs had to cut open a full leg cast because my leg was still swelling more. Didn't Believe me until the cast popped open and they saw blood all the way along. Still visible scar over 20years later.
That would probably be an incompetent doctor. Cast saws absolutely can (and do) cause minor burns and cuts when properly used, but a serious burn or something indicates operator error, most likely from dragging hte saw along the skin. The proper way to cut a cast is by a series of cuts into teh case from the outside moving down it as you go (think like an old style can opener: make one cut, move a bit, cut again, move a bit, cut again, etc, etc) not a cut along the. This both gives the blade constant breaks and keeps it from being in contact with your skin for extended periods.
This exact thing happened to me as well. I think I was 8, they assured me it couldn't possibly be cutting me even though I could feel it hurt and told them. I let them keep going, I had a pretty high pain tolerance for a kid (I had lived with the broken arm without treatment for a week before telling my parents I had hurt it - oops). Then when they cracked it off I had a 2inch burn and they felt pretty horrible. I still have that scar.
Hi steve, as a biomedical engineer specialising in soft tissue biomechanics, id like to point out that the conversion from shear to youngs modulus only is valid for very low deformation settings. This is because it assumes a linear relationship between stress and strain in the material.
Long ago in a galaxy far away while working in orthopedics I used to remove casts and split them to relieve pressure. I would demonstrate how the saw works first on my arm, and then allow them to touch the blade. The adults were worse than the kids. Our system had a vacuum that almost made more noise than the saw. Those were interesting days.
Adults are _always_ worse than children. Children are capable of following simple directions and are easily appeased and distracted. Adults don't think they _should_ follow directions, and can often be so allergic to information that you can't even get directions across, much less get them the hell out of the way of danger. Children don't have overinflated egos and a sense of entitlement, they're the kind of dumb that's easy to manage.
As a kid one of the coolest toys I ever had was a balsa wood working kit with dinky lathe, sander, drill and jigsaw. I think the way they made the jigsaw child friendly (Something I remember deliberately testing many times.) may well be the same way they made this medical tool safe.
I still fondly remember when I got my first cast off at around 8 years old, I was with two of my best friends who were insanely scared with me when we saw the saw that was gonna remove my cast, but our eyes were wide and amazed when we saw the doctor demonstrate the saw on his own hand, showing off how it hadn’t been cut at all when he put it on his hand.
I think it's important to note that different skin types are important, especially the sensitive skin left underneath the cast after injury. I'm very lean and when I got my cast off the person taking it off left the saw in place for too long and it burned my arm in two places, didn't hurt but still have the scars.
I've never had a cast but my brother had one when he was young. Watching it removed was traumatic for me! You solved a huge mystery. I can begin healing now.
I remember having to get a (fibreglass) cast when I was younger and I was rather scared of the saw until the guy who was taking it off showed that it could not cut skin…I have been wondering why it can not for a while now so thank you for explaining. The guy who took it off (then put on a new cast because the other one was not great) was really nice and I am glad he was the one to do it.
my grandfather had an experience once where a doctor was cutting his arm cast, and he felt it cutting through his skin. he tried to tell the doctor this, but the doctor didn't believe him. it was only until the cast came off and he saw blood that he believed him. wild stuff.
I had a cast for a broken arm when I was 8 or something, and since then I've always wondered how those saws work. It's just been one of those unexplained questions that I had in the back of my head for so long, but never pressing enough to actually research it you know. But I've stilll always been so curious and wanted to know! So thanks for solving that great mystery for me haha
I feel compelled to share that I am an outlier in that when I was about 11 years old I did actually get an injury on my left arm from a cast saw and I still have a pair of scars to show for it. That was close to 2 decades ago. I remember complaining to the operator and being told that it couldn’t hurt me, and then being vindicated when they got the bandages off.
You are not alone. Broken wrist in the late 90s. Exact same scenario. Horrible pain, being told, I was wrong and it could not hurt me, only for cast to come off and my hand covered in blood. Scar is barely there some 25+ years later, but it for sure cut me somehow.
@@Digger813 It sounds like the cast was on so tight the skin couldn't deform. Being held tight the saw was able cut thru just like the blown up balloon. kinda like holding both sides of some plastic wrap tight so you can cut it.
What an amazing coincidence-I only just talked to someone who had the same experience. She also got nicked by a cast saw as a child on her left arm, but somehow she ended up getting both cut and burnt. It's definitely a rare phenomenon and she must have been really unfortunate, even compared to other people who get hurt by those saws. If I remember correctly her injuries came from the fact that the padding material under her cast was not evenly distributed and there was not enough of it in the area where she got her injuries.
I've heard of horror stories from people who had their casts removed yet somehow still got cut by the saw, and sometimes the person cutting their cast say, "No way, this saw isn't designed to cut skin," and denying it even though some of those testimonies have the op bleeding.
I'm one of them, looking at the scar currently on the hand that's holding this phone. Just a little contact patch of the blade though at the base of my thumb.
I’m one of them too and still have the scar, she thought I was feeling “phantom pain” because I was scared of the saw :) nah, the saw was too old and cut my skin, I have the scar to prove it and I threw up from stress while it was happening
When I had a cast removed as a kid the doctor actually put this tool on his own skin to show me it was safe. I was absolutely terrified before that. Thanks for reminding me of that experience :D
The trick is to touch the blade *before* starting the cut, it's why the doctor showing off how safe the blade is always starts it up and touches it a few times to reassure the patient like steve did here. Problem is, once you actually start cutting, the blade heats up FAST. You can get a very nasty burn from one of these if it touches your skin close to the end of the cast cutting process. The blade doesn't have much thermal mass, so you are fine if the nurse regularly stops the cut to give the blade an instant or two to cool off, but if they're in a hurry, doing the cut all in one go, and sloppy about depth.... some nasty burns are pretty much guaranteed.
I broke my arm when I was 10 years old and I’ll never forget the dr who took my cast off pressed it to my skin and told me it couldn’t cut me. He was such a nice guy who made me feel incredibly comfortable. I’m 28 now and about 5 years ago he committed suicide💔 I will never forget you Dr Garland for your soft spoken voice and making me realize this blade wasn’t gonna hurt me 🥲
happened to my child dentist too poor guy he didn't end himself though but was killed by an elevator he was such a nice man still miss him when going to the dentist may they both rest now
I remember years ago when I was a teenager one of the nurses cut my cast off, and she burned the crap out of my arm. The cast back in the day weren’t these thin fiberglass ones they were made out of thick plaster, I can definitely attest to the heating up of that blade going through all that plaster. Left two nice straight burn marks along the cut line😅 I can say, though I’ve had several casts over my lifetime , and that was the only time that’s ever happened.
As someone who’s never had to wear a cast or even visit the ER other than for a regular check up this actually put my mind at ease because it was a slight fear of mine that if I ever wore a cast and the doctor slipped up I’d have a worse injury than before
Don't be mislead: if you slide the tool as it is powered, it'll absolutely cut through skin, It's not ment to be operated in a sliding motion, rather it's repeatedly prepositioned for each cut, but not moved while it's touching the skin. Like you put one dot at a time with pen & paper to form a dotted line
Once upon a time long, long ago, I attended the post mortem examination of an old lady who ended her own life by a shot to the head. The pathologist hauled out this "angle grinder" and proceeded to cut off the top of her skull, the way you'd cut off a cast. (This is necessary to examine entry and exit wounds, and makes wound track location easier, too.) There were two things that stuck with me from that. Whenever I remember, I get a little bit sad that someone could get so lonely and sad. And secondly I used to wonder how on Earth that saw did absolutely no harm to her brain. Now I know. Thanks.
Excellent script, my man. Most of the videos with appealing titles/thumbnails don't get into the subject so quickly, and you did it very well, and then proceeded to amaze us with much more information and knowledge about it. Ty c:
from the beginning I thought I had to watch the whole video to understand it, but this man didn't bother to give us what we wanted, thank you my friend.
A lot of people so have a similar tool to this at home, though: An electric toothbrush One I had as a kid (if you removed the replaceable brush head) would drill itself right into the plaster of the wall. My parents weren't big fans of this fact, but I learned something XD
There's another kind of oscillating tool that's very widespread. Oscillating saws have become extremely common in the power tool business. They're actually quite similar to that cast saw. You can go to any hardware store and find a wide variety of them from all the major brands. Very useful tools for detail work or cutting in confined spaces. Wouldn't use them for cutting off casts, but theoretically you could.
I really appreciate how this video is both really great edutainment for myself while just browsing youtube BUT ALSO it can be an incredibly powerful tool for helping people with anxiety about getting their cast removed. Your visuals and story telling are so easy to understand and follow that I believe this video could be fantastic for young kids who might be afraid when they're getting a cast removed. (And honestly probably even adults my age getting their cast removed too :p)
I was 12 and saw the doctor pull one of these out and I feared for my life, he then demonstrated it on his skin to show me it’s safe. The few seconds I spent not knowing that was the most terrified I’ve been in my life.
Except when I was having my cast taken off as a kid, the doctor kept moving it along the cast really fast and ended up cutting me a bunch. I kept saying it hurt and they said "No, it doesn't hurt you". Had scars from that for many years.
That's appalling! Scars both mental and physical I should think. My brother had to be catheterised regularly and he had one nurse who did it badly and he told her she was hurting him and she said "oh everyone says that" YEAH WELL THEN LISTEN TO THE PATIENT maybe?? Man I'm angry for you, I hope you put in an official complaint.
I had the exact same experience! It was in second grade, and she cut my arm in 3 different places which ended up getting so badly infected my hand swelled up to the size of a balloon and had to be hospitalized a week later. At first they were convinced I must have been bitten by a spider or something and it wasn't until the second day in the hospital they they realized it was from the infected cuts.
Plaster of paris is still preferred over fibreglass for a new fracture. I'm not entirely sure why, but I think it has to do with PoP ability to allow the limb to swell without cutting off blood supply. PoP is used excluisively in ED to stabilise fractures before surgery/imaging. The fracture clinic wouild give you a fibreglass cast to replace a PoP cast once the risk of swelling has gone.
The first time I saw this difference between solid and squishy things like people, was when I started at an auto parts store. My boss told me to hold this engine part in my hands while he removed a bolt with an impact wrench. I didn't know how it worked and thought it was gonna try rip the part from my hands, and I braced for it to twist hard. He said "No, relax, it doesn't work that way" and torqued the seized bolt right out of it while I wasn't even ready, it just shook a bit and didn't twist at all. It was the coolest thing ever
My little brother had a wicked scar for the longest time from a cast saw that either malfunctioned or was used incompetently by medical staff. I wasn't there but according to the story he was screaming the entire time and the doctor kept telling my mom he was just overreacting until the cast came off.
I cut my son’s cast off with my oscillating saw last summer. It was due to come off and the next available appointment was a couple weeks out. It was pretty fun to remove, and having watched several of my casts being removed previously helped with my technique. We both also wore masks to avoid breathing in the fiberglass dust.
The main reason for the cutting ability of this tool is the impedance matching between the blade and the material you're trying to cut. Only if this condition is fulfilled, the impulse and hence energy is successfully transferred to the material. You have the same effect if you leave high frequency coaxial cables open or shorted at the end.
While I may not understand all the math behind your research, I appreciate you breaking down complex scientific questions and make them more consumable for people who are naturally curious about everything in life. Thank you for your hard work.
Hey, Nice vid! Just a small correction, I believe the thing you are measuring is the particle velocity and not the speed of sound in your skin. Particle velocity is dependant on the impact velocity, where as the speed of sound in the material is an intrinsic property of the material, based on the density and stiffness. Also just consider that the speed in sound in air is approx 300 m/s, and this increases with density (e.g. water is approx 1500 m/s), so there is no way that your skin has a speed of sound in the order of 10 m/s.
Great Video Steve! I was always wondering how they make sure to not cut your skin. I think it's kind of funny you mention proprietary batteries on power tools at 6:23, while showing a Bosch driver using the ALL 18V Alliance battery system that aims to make batteries of different manufacturers MORE compatible, thus not being proprietary.
I used to work with these saws in my job and everyone said they don't cut skin but I DID NOT HAVE THE NERVE to test it. Glad to see you prove it first!
I've got an wrist fracture few years ago. Didnt expect this video to pop up in my recommendations. I expected that a cast have a special material that only cast can cut but wasnt expecting that the saw moves quickly at a small distance that cut rough material. Interesting video!
I had casts put on my limbs numerous times in my life and each time when the time came for them to be taken off, I always feared that this time doctor would chop off something important along with the cast. Thank you!
This unlocked a memory from kindergarten in 1997 when we had a demonstration of this in class and every kid was scared to try but it was so fascinating!
A point of note about cast materials: plaster of Paris is much heavier than the fibreglass casts, which is why it is preferred for fractures which need to be set for a long(ish) period. However, depending on when you attend A&E, you might still get a plaster cast as a temporary fix until the fracture clinic can get you in to set your break using fibreglass.
Broke my arm as a kid on holiday in France. When it was time to get rid of the cast we visited the local hospital. Was terrified and couldn’t understand a word from what they were saying. This kind lady took the saw, turned it on and before she started to cut the cast, she held the running saw against the palm of her hand. Felt like pure magic…
One thing I forgot to mention is that the blade can get quite hot from friction. Another reason not to try this at home!
The sponsor is Henson Shaving: Get 100 free blades here: hensonshaving.com/stevemould when you buy a Henson razor with code stevemould
When I was a kid the doctor said I shouldn't worry because the saw doesn't cut trough skin... I still have the scar from the burning it did on my arm though.
trained professionals @@astropgn
How you use an 18v open standard power tool battery that works on multiple brands to try to make your razor point ^^
@@astropgn Me too. My scars are 30yrs old and my cast was made of the catalyzed fiberglas instead of plaster of paris. at least it also cauterized the wound it made but it also pushed the fiberglas dust into it. was crazy itchy for longer than I had to wear the post cast removal wrist brace.
My second wonder was, why use a circular blade when only a fraction of it sawing
I only had a cast once when I was like 8 or so years old, and I was terrified at the saw being used once it was healed, and thought for the longest time that the doctors were just THAT precise and skilled with the saw xD
They are. This video is supposed to be a prank.
@@GardenGuy1942 cast saws cant hurt you
@@guymanhumanperson they can cause cuts sometimes. but its very rare
I also had a cast (two actually, both ankles as my Achilles tendons were not growing fast enough), when it came time to cut the nurse asked me if I was afraid, and when I reluctantly nodded my head she held the thing to her arm and let me watch how it just tickled.
@@MrRandoOnly if the doctor moves the saw too fast. Human skin is pretty elastic, but if one moves the saw too fast, the greater pull of the saw teeth overcomes the elasticity of the skin.
My first job was with prosthetic limbs, we made a lot of casts, most people almost had a heart attack when I pulled out that baby, was really hard to convince them it was safe. Neve knew exactly why it was safe, thank you Steve for that!
Neat!
...Why do they have people operating those things without telling them how they operate lol. It's not that complicated... tl;dr "It just twists back and forth and the actual disc isn't that sharp, so all it does is scrape plaster and soft stuff like skin isn't going to get cut."
This would also hopefully prevent the issue in another comment where some medical practitioner was running the thing back and forth along the cast so fast, that it actually caused skin scrapes ._.
Surely it would be really easy to convince them that it's safe: just put it on your own arm.
@@karlhendrikse That's what was shown to me as a kid. 100% fear shifted into 'what the everloving fuck how does that work I MUST know'
@violetscott2322 thats what they did to me, too! It actually made me want to become a doctor!
This made me remember when I had my cast removed from my leg when I was a kid and was terrified of the saw and the nurse taking the cast off took the saw and pushed it right up against her own arm to show me that there was no risk of harm. It's something that immediately put me at ease and I let her continue without even so much as a flinch. I hadn't thought of that until this video. Thank you for reminding me of what looking back is a really fold memory.
You were lucky. As a 6 or 7 year old who broke my leg, the person who took the cast off seemed to enjoy my state of near panic as he held up the saw and started to go to town. Maybe I got a sucker out of the deal!
I saw a nurse do that the first time I saw a saw (🥴) and I think it's probably something that happens literally every time the saw comes out of the cupboard.
Same. I was 5 yo. Helping my dad trim a tree by carrying the branches away. Tripped and broke my arm by falling from my own height. Doctors discovered I had brittle bones then.
When I took off the cast, nurse saw my eyes widen. I didn't say a word and she said whyle pressing the saw to her hand "Don't worry. It doesn't hurt. See?".
I broke that same arm again the day I took off the cast riding a bike LOL. Wasn't scared of the saw the second time.
@@ThZuaoDamn, that is insanely unfortunate. Can't help but giggle a bit.
@@ThZuao I was afraid that story might continue along the lines "...the same day we continued trimming the tree and I demonstrated to my dad what the nurse had done by pressing the chainsaw to my hand saying, 'don't worry, it doesn't hurt'..."
I had a random doctor cut off my cast in under 3 minutes. He showed me and put that saw to himself before touching the cast. I trusted that doctor. Now I finally know the science behind that.
Exact same story here.
About 60 years ago I had a little mishap resulting in a lower arm cast. When I went in to have it removed the doctor came in, and without saying much, turned on what looked like a rotary saw with the blade spinning and pushed it toward the cast on my arm. Before he contacted the cast I had his wrist fully clamped in my good hand, thinking this maniac was going to slice my arm with his crazy saw. The doctor's reactions were astonishment, then anger, then he laughed and put the saw on his own arm to demonstrate how it worked. So we both got educated; I learned about oscillating saws and he learned that patients may need to understand what he is about to do to them.
Incredible story. While I would hope this would be less common today than 60 years ago, it's funny to think that doctors would go straight into some sort of procedure (since they're the trained expert) without explanation, which would look like attempted disfigurement to most people.
I had my first cast at 11 and was very inquisitive, asked about every step and just really wanted to know what was going on (really more from curiosity than a focus on my wellbeing). First time a cast was taken off, I don't remember being scared of the saw, but thinking "Either this is going to hurt, they're very skilled with a spinning saw, or there's something I don't know". I just asked how it worked and if it would hurt because I wanted to know, but if I didn't have that experience until I was an adult, I would absolutely have gotten defensive before the saw could take my limb.
@@Faustvonholle My experience of most doctors today is consistent with the story, we the patients don't need to know anything, they will do onto us as they think is best.
@@Dreadought I hear what you're sayin you think it is, but how bout some antibiotics instead?
I had several fractures as a child and the man in the hospital who cut the casts of was super friendly. It looked like a really fun place to work and they were all jolly in that department. He always demonstrated the tool on his own arm to reassure the terrified children.
@@freshrot420 How about a cool opioid addiction?
I have to say, I really appreciate that you took the time to explain _why_ trying this for yourself is dangerous and _how_ it could get you hurt, rather than just giving a boilerplate "Don't try this at home".
xD
I mean almost anytime I've heard someone say to not try something they've explained it. Not like you can't do both lol
Yeah but don't they make those oscillating tools for cutting tile? Pretty sure he said Dremels were out, but as long as the tool oscillates you're good.
@@SpaghettiEnterprisesNo. An oscillating tool can oscillate too far and still cut skin.
@@SpaghettiEnterprises"as long as the tool oscillates you're good"
Not what he said at all!!!
Wow I’m never using a cast saw to shave again! Those differences were insane lol
Same, I can't believe I've been making this mistake my whole life
Don't be so dramatic, just sharpen the blade.
Bah! Barely noticeable!
I couldn't see any difference. Gonna stick with my reciprocating saw.
seek therapy@RepentandbelieveinJesusChrist5
“Shit wrong saw”
Famous last words💀🤣
Bruh used a circular saw grinder💀
🌓🐽🌗
💀
Bro used a band saw, or a drop saw
I remember being terrified of having my cast being cut off and the doctor just ran it across his arm while it was on and I was like “…oh” and I was fine. Honestly props to that doctor he must have had so many terrified kids coming in
I remember my doctor attempting this and then he demonstarted on my arm and managed to break skin somehow
@@HighCoupDeTatYour skin just had a terrible case of skill issue
Well in my country people are poor and we are like 20 years behind in termsn of technology so we don't have saws like that. And I've had a broken foot and what they do is they use a regular saw (I assume), because they insert a metal shin under the cast where they will cut and so if they break through the cast they will scrape the metal shin under it. The shin is thin however and I still feel like if it's somebody that is inskilled and moves slightly to the side outside of the metal shin area it can still cut into your body part :D
@@warrior1477 what country
@@HighCoupDeTatdo you ever use body lotion? If you don't that might be why
As an 11 year old in 1987 I vividly remember the doctor holding the case saw against his own arm to show me how it wouldn’t hurt me. Several casts and metal screws and plates from that broken arm I came to trust the cast saw and my doctor.
Side note, I saw that same doctor more than 30 years after my broken arm and upon introducing myself as soon as he heard my name he immediately grabbed my left arm to inspect his work. He 110% remember me all those years later. Thank you Dr. Golden.
Idk why you people really need internet approval so much to make up these stories 😂
@@AlexandreGwhy would it be made up?
@@AlexandreGI had a shit this morning. Do you believe me?
@@laurenanderson7330 of course, I was inside your whole peaking by the little whole I made. If you don't mind, next time pull down your pants more sensually, please
@@laurenanderson7330no, women don't poop or fart
Hi Steve, minor correction from a UK Emergency Medicine Doctor. We still use plaster of paris as opposed to synthetic casts when you first break a bone. Plaster is better for the initial molding around the break. We also apply plaster to only one side of the cast, this is called a backslab. The soft side then allows for any swelling that occurs. This is usually then changed to a hard synthetic cast a few days later.
That's very interesting, thanks for explaining! I only had cast as a kid (so... definitely more than 15 years ago since the last one now), and it was always only plaster of Paris, so I wondered about the modern stuff :)
Hi, David. Thank you for your comment. Could I also humbly ask you: what is the purpose of the change from plaster to plastic if in few days plaster is already fully solidified?
@@NikolayBychkovRus I presume they have to redo the cast because swelling has gone down and it would be loose, and since there's no chance of it swelling up again you can use the faster cast (that sounds like a great trade name)
Interesting, can I ask why? Is the synthetic cast less secure?
This is just a guess, but I would think the synthetic would be better in handling getting wet. I am not saying you would run water over it or soak it, but it could potentially handle getting wet (splashed not soaked) better than a plaster cast. Again, this is just a guess. I have never had a cast, so I have no personal experience with either.
Honestly, this is the first time I didn't completely dislike a "sponsor section" of a video. The information was - as always well presented, concise and relevant. Thank you so much for making those videos!
My thoughts exactly
No te olvides de usar el código de descuento
I was actually interested and did not skip it.
the doctor explained this to me when he cut the cast off, but I'm glad to see someone such as yourself explaining this for the people that don't know, and you did it in great detail as well.
Your doctor knows a lot of physics
I had a cast once and the doctor didn't explain it to me at all. Part of me was terrified that I would have my whole arm sawed off.
lol, well he didn't explain it in detail, but he did demonstrate that the blade won't cut skin. @@JustDinosaurBones
Haven't had a cast yet, but in the field of automotive repair we use something similar, which also oscillates to cut out body panels for less heat buildup to avoid it from warping.
However, it might actually get through skin at some point since it isn't designed for casts 😅
oh, you poor thing. The trauma@@olivercharles2930
That comment about trying to find material properties of skin really hit home. I’m a bioengineer, and in college I first learned about regular materials, which are linear (behaves the same at different scales), homogeneous (all made of the same stuff), isotropic (same in all directions), and elastic (doesn’t lose energy when stretched), all very nice properties that make solving problems easy. Then I got to tissue mechanics and realized human bodies are none of those. In fact they’re so complicated the best we can do is ever-more-complex approximations that kiiiiinda work for very specific pieces and nothing else.
So, instead of a spherical cow, it's a planar teat? Heh.
*Isotropic. Isotopic would be "about isotopes".
Also, it should be considered that skin (like many other biological tissues) is under tension on the body and this influences the wave propagation speed
As a fellow engineer, spoiler alert: they're all just (very good) approximations, some are just messier than others.
@@SeanTerisuthis sounds like a pessimistic version of George Box's quote "all models are wrong, but some are useful"
This is exactly why the Dremel oscillating multi-tool, with an 80-grit sanding triangle pad, is great for exfoliating heels. The soft skin jiggles. The thick, dead, calloused skin isn’t as pliable, and hence it gets sanded off (slowly).
But wait there's more!
Fun Fact: If you have really dry skin, your skin loses some of that elastic pliability and become susceptible to being cut again.
I remember learning this from another TH-cam comment section where a medical professional was sharing their experience doing demonstrations with the cast saw for kids, as a way to help them relax beforehand. However one day when they were preforming this demonstration on their hand like they normally would, their hand was somewhat more dry than normal, and they managed to actually cut themselves, much to the horror of the child they were attempting to calm down haha
An angle grinder works really well too except you often end up needing stitches :)
Man, you are awesome! I just bought a Makita oscillator multitool for my father in law, but looks like mother in law also will like it! ;)
@@NikolayBychkovRuspause 🤨
Man that first freeze frame is priceless. Also the half beard. I can say that this is the most hillarious video you've made that I've seen.
it's a magic saw cuts through the cast but not your flesh
For those without facial hair: Even though the differences in hair length on each side are difficult to notice on camera, the actual smoothness of the skin, as well as irritability after shaving, make a world of difference.
Regardless of brand, for pure clean face shaving safety razors are just better; the only reason to use a plastic razor is if you didn't know any better yet. If you were doing some more shaping and grooming of the facial hair, you'd have more room for electric razors.
Clearly the smooth shave off the cast saw is much preferable, and way better looking too!
I'm not sure if I was clear, English is not my native language. I was talking about a razor in the style of the old razors used by barbers, except with razor blades, so you don't have to deal with the sharpening.
@@jankoodziej877 I believe those are called straight razors, and yeah if you know how to use em they're deadly effective cause they cut real clean and the typically load half a blade so you can just keep the other half clean and wrapped up for the next time you need it
@@sohamsengupta6470 yes, exactly what I was talking about.
The sponsor spot was real eye opener. I've been shaving with a cast saw for most of my life and you finally got me to switch. I'm so happy I did.
It's waiting for the plaster of Paris shaving "cream" to set that is the onerous bit...
I remember having my cast removed and asking the lady in so much fear "that doesn’t cut through skin???" And she looked me straight in the eyes, turned the saw on and pressed her hand on it and I honestly started laughing with the nurse and my mother
You're lucky, my doctor just said "I haven't cut anyone.... yet" Child me was terrified
ohhhh bro @@Exsonius
Yep if they felt it and believe it they know they can press it on there skin and show you look it’s moving back and forth so little your skin moves with it. So it will only cut hard things on the surface.
Modern tools today I believe no matter the brand this tool won’t cut you and is it did you would have to really force it plus it wouldn’t even be mm deep it can hardly break the skin if you try and I’ve used many different brands from other people on the job. I do admit the best ones can hurt you a little faster but still really cannot hurt you. You won’t bleed at all for a minute then when you do it’s nothing and definitely less than you could ever do shaving.
Just breaks the skin slightly and is not dangerous. The attachment they use make it look rotary tho. It’s just for blade life and angles they can use still in it. They get better stuff than we do lol. But we can but similar also we can buy softer and give them a new edge with our drill attachment over and over until they become too short. You wouldn’t want these shavings in a human being I’m sure lol. But it’s same deal can’t break the skin and by the time it does you won’t know for minutes. Like when I guy is too rough with the clippers and later you get a couple little scratches. It’s about the same hard to really hurt anyone just good for hard objects. Maybe a shin bone but they gonna get away or kick you unless there tied well lol.
I usually don't like sponsorships clips in videos, but this conclusion for the shave quality was hilarious. Also the video was great as always.
That transition at 6:01 is absolutely amazing. You, sir, are a treat.
anoobis
Cast saws CAN cut skin. If one were to move the saw along the surface of the skin, you would move it beyond the elastic limit of the skin. When removing casts the ortho tech or medical assistant (the doctor usually doesn't do this) presses the saw into the cast perpendicular to the skin, then withdraws it when they feel it break through the cast. After withdrawint the saw to the surface of the cast, it is then moved and pressed in again. The layer of padding under the cast is usually sufficient to protect the skin from the teeth and fron the het.
Absolutely, I got cut several times when they removed my cast when I was young. It was very hot as well.
@@bid0u12345 probably it was wrong one or faulty
I have a 35 year old scar on my wrist from a cast saw. Many things can cut you if used incorrectly or not maintained.
Aye I have a scar as well. It wasn't a problem, I just had a stuck partial cast that needed a lot of work to remove.
God I hate when the het hurts me
There is a similar oscillating tool meant for safely "buffing" your eyeball. Yes you read that right. I found that out the hard way. I got a shard of metal in my eye ( while wearing glasses AND safety glasses) and there was rust left just under the surface. They use a contraption to hold your lid open and buff away the spot without causing damage. They numb you with drops but you get to enjoy the experience while awake and watch it get closer..... Happy nightmares everyone.
Cheers for that.
I got hit in the eye with welding slag despite wearing safety goggles, and after that I always kept my welding mask down while chipping slag off.
Sounds like something right out of Saw 😂
Oh god no
Agh reading this is making my eye twitch yuck
1:50 That actually looks like it’s really good for itching…
Fr
I'd absolutely buy a product like that
A fun memory from when I was 5- -I was having a cast removed around my chest, and was, naturally, freaked out by the idea of a saw being brought near my body. The doctor, wanting to ease my panic, enlisted my mom to demonstrate how safe the saw would be, by showing it in use on her arm. Didn't spend anytime explaining the physics of this to her though, so my mom was the one panicking instead, though reluctantly trusting that the doctor wasn't about to slice her arm open. 😅
how do you even get to a point where a full body cast is needed mate
@1v966 Open heart surgery was what I was in for, though my wording there was a bit off-
Was just a cast around my torso, not "full body". My apologies. Lol
why can't the doctor just show it on themselves
@throwawaypt2throwawaypt2-xp8nx If I had to guess, to dispell any thought that he was somehow putting it close to him, without actually making skin contact. Otherwise, probably for comedic effect.
"Don't worry, kid, I'm going to scare the crap out of your mom instead!" -the doctor, probably.
I am an orthopedic surgeon and cast saw injuries are quite common, even when an experienced person is using them. At my hospital there have been severe injuries.
If you press the oscillating cast saw against a person's skin and then slide it, you will slice right through the skin. The blade can also get extremely hot if it is dull and can cause severe burns.
i was wondering about that; sliding it down the cast while cutting it and if it was in contact with the skin. thanks for your insight :)
Thank you for your comment. I had injuries on my leg twice from having casts removed. It was like a burn from my thigh to my ankle and it hurt like hell while they were doing it, but the technicians scoffed at me and said it was all in my head. Now I know what it was - they were burning me with the saw because it wasn't sharp enough.
Thank you! I had a cast removed on my arm as a child and the doctor‘s assistant absolutely burned my arm.
I got my cast cut off by an old cajun ortho when I was a kid. The dude told me 'if it cuts you, you can punch me'. Well I jumped when the blade went through the cast and it cut me. I didn't punch him though, he was a nice dude.
I don’t mean to sound too flippant, but it seems like you’re just describing Malpractice. They are operating the saw in a way it wasn’t intended to and causing harm because of it.
Do you have any idea just how therapeutic it was to watch this video?
Growing up I was terribly afraid of breaking a bone and getting a cast, not because of the pain and immobility that'd be involved, but because a power saw would be used to remove the cast. The thought of the saw scared me more than anything. I only _now_ learned that all of that fear was for nothing.
I feel like a weight has been lifted off of me, thanks to your video.
Well, fear no more! You can now enjoy the full experience in breaking a leg or two, getting a cast, have your friends and family leaving their signatures and drawings on it until the big final moment of removing it and you have a leg as good as new!
Jk lol.
It's such a liberating feeling when we discover these things that we've been afraid of and realize they weren't as scary as we thought. I'm happy for you, man. 🥳
yeah idk, I'm currently looking at the half-inch scar on my wrist from being injured via cast saw almost 10 years ago. I was in middle school, I vividly remember screaming at the sharp pain and the doctor looking at me like I was crazy. Beginning to wonder if they even had the right tool lmfao
I misread the title as “i cast saw on human skin” like its a freaking dnd attack spell
wait me too 😭
i cast, MEDICAL BILL!
@@Xedronic new us medical system where a d20 decides if you live or not and the price
This was possibly the most perfectly timed video recommendation of my life. I'm actually going to the doctor tomorrow where I'll very likely have the cast on my leg removed and I would have flipped out at what looks like a rotary saw being brandished by my leg. I am not a brave person lol
Edit: They cut the cast with the exact same tool. The video did help a lot.
W
Because TH-cam has your searches and schedules bugged
@@noneofyourbusiness4133never had a broken bone, haven’t been to doctors in years.
No talk or search relating even closely to this video.
When i got my cast off as a kid, the doctor explained that the saw vibrated instead of spinning! It helped me be not so afraid of the saw lol
I heard that, but I thought he meant it vibrated sideways. It was cool to see the slow-mo definitively explain what was going on.
When I got a cast off as a kid the guy just told me it was a magic saw that liked people and would never cut anyone.
I believed this, somehow.
@@mahoganywolf8843 haha cute
my doctor used the saw on herself to show me it doesn't hurt
I was so afraid when my cast was removed. The assistant did say the saw does not cut my skin but I did not trust her as a kid. That thing looked dangerously like a mini circular saw. Showing me on her skin would probably have helped.
I’m loving all the comments of people sharing happy stories with doctors demonstrating the saw on themselves before using it on them. I never had a cast before, but as someone who is often terrified of medical equipment, that kind of understanding and demonstration is way more helpful than the doctor just apathetically saying ‘don’t worry’ and going for it when it’s clear the patient is confused and concerned.
99% of times it because the saw is in bad shape and didnt got any good treatment @@BlakeN-o6l
They don't cut you, but if the cutter goes too slowly, the blade can get hot and burn you a bit. I remember a very slow-moving nurse trainee having to remove a cast from me, cutting super slowly, and the blade wicked hot from the friction and burned me. An experience ortho, however, removed one of my casts like he was opening a zipper.
It's good to see someone in the shaving industry finally taking on Big Cast Saw .
Fun fact: 1976 a carpenter got his cast removed with this tool and seeing it's potential to reach and cut in difficult places, he sought to buy it from the doctor and took it to the construction site. That's how the cast saw became the oscillating multitool.
So what you're saying is I should use a oscillating multitool to cut off my cast?
@@oliverer3you could very well
@@oliverer3 please dont
That is probably not a good idea. If the general principle us the same, the spécifications may differ, as explained in the video.
Fuck. Yeah.
Do it!
It's one thing to have them casually explain it in the doc's office, but to actually *see* how it works in slow motion and how that relates to direct contact with skin is incredibly useful in fully understanding just how safe it is. Doctor's should recommend this video to anyone worried about getting their casts cut off!
100%
I use an oscillating cutting tool pretty much every day for remodeling work. It cuts effortlessly through drywall, wood, vinyl, etc. It's a classic move to stick it on our skin when we're working with a new guy and watch him freak out.
This is almost astoundingly coincidental to me: My son is having casts put on tomorrow for stretching his Achilles tendon and I was telling him about how they take casts off and , lo and behold, I get a ping for a suggestion to your video. Made a perfectly timed learning experience, for both of us.
Keep em coming, you always find the most interesting things in the obvious that you typically don't think about
You've probably discussed the cast around your phone, neat and freaky at the same time!
@@steinblitz1506 considering i often see notifications come hours after ive already watched the video it wanted to notify, that definitely sounds like the algorithm listening in
I actually had that exact surgery about 3 years ago! Wishing for the best!
@@kirtil5177 that's my normal go-to conclusion, but it did just get released and I do have notifications on for this channel, so unfortunately I can't claim that this time. This time...
@@claymcgranahan thanks! All went well, now he's looking forward to getting his first casts removed so he can see the saw, ha
Just FYI: a plaster of paris cast is usually used on a recent fracture because it lends itself more easily to putting on a cast splint rather than a circular cast which allows for post-traumatic swelling. Synthetic casts are used for circular casts, which is shouldn't be put on any earlier than 5 days post-trauma.
I understood nothing of this, but I appreciate the information nonetheless.
Petition for Steve to do a full body cast of himself. A Steve Mould if you will. I'll show myself out...
Booooo just kidding, that was pretty funny
0:47 That's not really true. My leg was put in a cast when I was 10. The nurse cut a groove down the front of the cast to make it easier to remove later. I screamed when it passed over my knee, but the tech insisted that the blade was harmless. Weeks later, when the cast was removed, we found a scar on my knee and a large patch of dried blood on the inside of the cast.
Oh the skin is weak
plaster casts are still used quite a lot, but for more serious injuries. they use chemical accelerators in it to make it set in an hour or so, its gets really quite hot as it does. only lesser injuries or later stages get the fiberglass ones. also you cant just get the speed of sound for your skin from the ripples since your not in the far field regime and the oscillations are quite clearly being powered.
src: im a physicist who had a lot of casts...
Two very interesting points. Thank you.
Oscillations are always powered by something. Oscillations through the air are powered by your lungs when you speak. How fast those oscillations travel is the speed of sound through air.
And by far field *region you're referring to the electromagnetic field around an object which would be relevant if we were talking about radio waves not sound waves. The speed of radio waves is entirely different from speed of the oscillation of compressive pressure (sound).
Hope this clarifies things for you.
@@waxywabbit1247 this is wrong, and i dont think you understand.
imagine this, you detonate a high explosive. the initial blast wave propagates at the speed of that explosive which is far higher than the speed of sound in air. once this hits air it will still go at that speed for some distance. this is called the near field, as you said this is also true for electromagnetic waves and is true of all waves. only after some distance will the blasts wave slow down to the speed of sound and propagate 'normally'.
with powered i meant that the oscillations are forced at that frequency and do not yet go at the speed of sound for that medium.
I'm hoping that the casts are not a side effect of the job. ;-)
I would also suspect that the fact skin is firmly attached to whatever is under it has a huge effect on the waves generated too.
Your sponsorship segment for this video is one of the best I have ever seen ever from anyone. Didn't feel forced or anything, just seemed natural.
100%, and the half-shaved face was a perfect addition
internet historian is still number one
And the GRAPH! Oh, the 📈
It was so casual like most of his humour, love it!
And as someone who's owned a Henson for about a year. I can attest to the quality
This is some great content and in content marketing. I really liked the scientific approach with east to follow formulas from strength of materials, and the merger with of the topic with the sponsor of the video was flawless. I did not skip through and might consider giving a chance to the shaver.
When I was a kid, I got a cast and when I heard they'd use a saw to remove it, I was EXTREMELY worried for several days and nights until the moment actually came... and it was perfectly fine.
That was maybe 35 years ago.
Thank you for making this video 😁
If I were the doctor I'd put a big show and say: "Watch out, kid, this will cut off your arm if you ever so twitch even a hundredth of an inch!" And then approach the cast veeeery slowly. (" oДo)
@@fsmoura thank f**k you're not a doctor
... Apparently they didn't always use oscillating saws, or I had tighter skin.
Still have scars. They're most visible if I get a tan.
@@hariman7727 the thing they forgot to mention is that as these blades lose their edge they generate more friction and get hot enough to burn through your skin... i've got scars as well and they've been there for the last 30 years
Hi Steve. I’m glad you made that comment about the heat because 40 years ago a doctor 3 nurses and my mother had to hold me down as they tried to convince me that one of those saws wasn’t able to cut me as they cut my plaster to loosen it from my arm. I still have the scar to this day which is about 60mm long. They may not be able to cut you but they can sure as s^*% burn you to the point that you think you’re being cut. My mother still feels guilty about not believing me when I was running around the room trying to escape these adults in my mind, hell bent on cutting through my arm! I can laugh about it today but not then.
They can actually do both
I had almost exactly the same thing. Drs had to cut open a full leg cast because my leg was still swelling more. Didn't Believe me until the cast popped open and they saw blood all the way along. Still visible scar over 20years later.
That would probably be an incompetent doctor. Cast saws absolutely can (and do) cause minor burns and cuts when properly used, but a serious burn or something indicates operator error, most likely from dragging hte saw along the skin.
The proper way to cut a cast is by a series of cuts into teh case from the outside moving down it as you go (think like an old style can opener: make one cut, move a bit, cut again, move a bit, cut again, etc, etc) not a cut along the.
This both gives the blade constant breaks and keeps it from being in contact with your skin for extended periods.
That might have been what happened to the person I mentioned in my previous comment,@@88porpoise .Well noted.
This exact thing happened to me as well. I think I was 8, they assured me it couldn't possibly be cutting me even though I could feel it hurt and told them. I let them keep going, I had a pretty high pain tolerance for a kid (I had lived with the broken arm without treatment for a week before telling my parents I had hurt it - oops). Then when they cracked it off I had a 2inch burn and they felt pretty horrible. I still have that scar.
Hi steve, as a biomedical engineer specialising in soft tissue biomechanics, id like to point out that the conversion from shear to youngs modulus only is valid for very low deformation settings. This is because it assumes a linear relationship between stress and strain in the material.
I understand that it's not dangerous but I would never ever tempt fate like that
Long ago in a galaxy far away while working in orthopedics I used to remove casts and split them to relieve pressure. I would demonstrate how the saw works first on my arm, and then allow them to touch the blade. The adults were worse than the kids. Our system had a vacuum that almost made more noise than the saw. Those were interesting days.
Poor adults might've had unexplained traumas
Adults are _always_ worse than children.
Children are capable of following simple directions and are easily appeased and distracted.
Adults don't think they _should_ follow directions, and can often be so allergic to information that you can't even get directions across, much less get them the hell out of the way of danger.
Children don't have overinflated egos and a sense of entitlement, they're the kind of dumb that's easy to manage.
As a kid one of the coolest toys I ever had was a balsa wood working kit with dinky lathe, sander, drill and jigsaw. I think the way they made the jigsaw child friendly (Something I remember deliberately testing many times.) may well be the same way they made this medical tool safe.
Found Ron Swanson
I still fondly remember when I got my first cast off at around 8 years old, I was with two of my best friends who were insanely scared with me when we saw the saw that was gonna remove my cast, but our eyes were wide and amazed when we saw the doctor demonstrate the saw on his own hand, showing off how it hadn’t been cut at all when he put it on his hand.
"Turns out the human skin is like an underinflated balloon..." Have you been talking to my wife again?
I think it's important to note that different skin types are important, especially the sensitive skin left underneath the cast after injury. I'm very lean and when I got my cast off the person taking it off left the saw in place for too long and it burned my arm in two places, didn't hurt but still have the scars.
I've never had a cast but my brother had one when he was young. Watching it removed was traumatic for me! You solved a huge mystery. I can begin healing now.
I remember having to get a (fibreglass) cast when I was younger and I was rather scared of the saw until the guy who was taking it off showed that it could not cut skin…I have been wondering why it can not for a while now so thank you for explaining. The guy who took it off (then put on a new cast because the other one was not great) was really nice and I am glad he was the one to do it.
my grandfather had an experience once where a doctor was cutting his arm cast, and he felt it cutting through his skin. he tried to tell the doctor this, but the doctor didn't believe him. it was only until the cast came off and he saw blood that he believed him.
wild stuff.
The half shave had us all giggling. Thanks for this video, it was something I always wondered about!
I had a cast for a broken arm when I was 8 or something, and since then I've always wondered how those saws work. It's just been one of those unexplained questions that I had in the back of my head for so long, but never pressing enough to actually research it you know. But I've stilll always been so curious and wanted to know! So thanks for solving that great mystery for me haha
unfortne man hope your ah o k
I feel compelled to share that I am an outlier in that when I was about 11 years old I did actually get an injury on my left arm from a cast saw and I still have a pair of scars to show for it. That was close to 2 decades ago. I remember complaining to the operator and being told that it couldn’t hurt me, and then being vindicated when they got the bandages off.
Sounds like a lot of people didn't understand this tool.. You're not the first one I've seen on here saying that.
Ouch. Were they just pushing too hard?
You are not alone. Broken wrist in the late 90s. Exact same scenario. Horrible pain, being told, I was wrong and it could not hurt me, only for cast to come off and my hand covered in blood. Scar is barely there some 25+ years later, but it for sure cut me somehow.
@@Digger813 It sounds like the cast was on so tight the skin couldn't deform. Being held tight the saw was able cut thru just like the blown up balloon. kinda like holding both sides of some plastic wrap tight so you can cut it.
What an amazing coincidence-I only just talked to someone who had the same experience. She also got nicked by a cast saw as a child on her left arm, but somehow she ended up getting both cut and burnt.
It's definitely a rare phenomenon and she must have been really unfortunate, even compared to other people who get hurt by those saws. If I remember correctly her injuries came from the fact that the padding material under her cast was not evenly distributed and there was not enough of it in the area where she got her injuries.
2:09 thank you for removing the audio effect of the baloon, so considerate
such a good cut 0:03
Is that pun unintentional?😂😂
made me flinch
Scared the heck out of me
Made me shiver
The video cut or the arm cut?
That's dedication, between letting the cast dry, growing and shaving the beard, and everything else, the things he does for us are amazing..
I've heard of horror stories from people who had their casts removed yet somehow still got cut by the saw, and sometimes the person cutting their cast say, "No way, this saw isn't designed to cut skin," and denying it even though some of those testimonies have the op bleeding.
I'm one of them, looking at the scar currently on the hand that's holding this phone. Just a little contact patch of the blade though at the base of my thumb.
Yep I have a scar on my hand thanks to the idiot doctor that cut my cast off. Dude was so rough he sliced right into my thumb and wrist
I’m one of them too and still have the scar, she thought I was feeling “phantom pain” because I was scared of the saw :) nah, the saw was too old and cut my skin, I have the scar to prove it and I threw up from stress while it was happening
I should have sued the hospital for neglect. I got traumatized of hospitals for a while because they cut the cast AND the skin under it...
Probably because their skin was too dry to stretch
5:20 no joke the formula on screen actually helped me with my strength of materials homework
The fact you compared the quality shave of your sponsor’s product with that of the cast saw tipped the balance for me. You just got a subscriber. 👏🏻😂
When I had a cast removed as a kid the doctor actually put this tool on his own skin to show me it was safe. I was absolutely terrified before that. Thanks for reminding me of that experience :D
The trick is to touch the blade *before* starting the cut, it's why the doctor showing off how safe the blade is always starts it up and touches it a few times to reassure the patient like steve did here. Problem is, once you actually start cutting, the blade heats up FAST. You can get a very nasty burn from one of these if it touches your skin close to the end of the cast cutting process. The blade doesn't have much thermal mass, so you are fine if the nurse regularly stops the cut to give the blade an instant or two to cool off, but if they're in a hurry, doing the cut all in one go, and sloppy about depth.... some nasty burns are pretty much guaranteed.
Probably what happened to me. I've got a couple scars on my arm from a cast saw.
2:26 Hey, now
What?
Thank you for FINALLY doing a skin Young's modulus reveal! I've been requesting that for YEARS
We desperately need to now if he revealed it to his wife as well
I broke my arm when I was 10 years old and I’ll never forget the dr who took my cast off pressed it to my skin and told me it couldn’t cut me. He was such a nice guy who made me feel incredibly comfortable. I’m 28 now and about 5 years ago he committed suicide💔 I will never forget you Dr Garland for your soft spoken voice and making me realize this blade wasn’t gonna hurt me 🥲
damn that took a very dark turn. was not expecting that. rip to him man damn
What a beautiful person! Rest in peace
happened to my child dentist too poor guy he didn't end himself though but was killed by an elevator he was such a nice man still miss him when going to the dentist may they both rest now
well *_that_* went from 0 to 11 real fucking fast.
@@redneck9202 by the way, peace means calm and quiet. piece means chunks and shards. we typically say "rest in peace"
I remember years ago when I was a teenager one of the nurses cut my cast off, and she burned the crap out of my arm. The cast back in the day weren’t these thin fiberglass ones they were made out of thick plaster, I can definitely attest to the heating up of that blade going through all that plaster. Left two nice straight burn marks along the cut line😅 I can say, though I’ve had several casts over my lifetime , and that was the only time that’s ever happened.
Same thing happened to me, although the burn is pretty small. I think doctors become overconfident and careless when using these saws.
@@450AHXor very dull blade and more pushing through than actual cutting...
talking about those moduli and Poisson's Ratio really blew my mind. First time I've caught them out in the wild and not at work or school haha
As someone who’s never had to wear a cast or even visit the ER other than for a regular check up this actually put my mind at ease because it was a slight fear of mine that if I ever wore a cast and the doctor slipped up I’d have a worse injury than before
Don't be mislead: if you slide the tool as it is powered, it'll absolutely cut through skin,
It's not ment to be operated in a sliding motion, rather it's repeatedly prepositioned for each cut, but not moved while it's touching the skin.
Like you put one dot at a time with pen & paper to form a dotted line
Once upon a time long, long ago, I attended the post mortem examination of an old lady who ended her own life by a shot to the head. The pathologist hauled out this "angle grinder" and proceeded to cut off the top of her skull, the way you'd cut off a cast. (This is necessary to examine entry and exit wounds, and makes wound track location easier, too.) There were two things that stuck with me from that. Whenever I remember, I get a little bit sad that someone could get so lonely and sad. And secondly I used to wonder how on Earth that saw did absolutely no harm to her brain. Now I know. Thanks.
Excellent script, my man. Most of the videos with appealing titles/thumbnails don't get into the subject so quickly, and you did it very well, and then proceeded to amaze us with much more information and knowledge about it. Ty c:
from the beginning I thought I had to watch the whole video to understand it, but this man didn't bother to give us what we wanted, thank you my friend.
A lot of people so have a similar tool to this at home, though: An electric toothbrush
One I had as a kid (if you removed the replaceable brush head) would drill itself right into the plaster of the wall. My parents weren't big fans of this fact, but I learned something XD
There's another kind of oscillating tool that's very widespread. Oscillating saws have become extremely common in the power tool business. They're actually quite similar to that cast saw. You can go to any hardware store and find a wide variety of them from all the major brands. Very useful tools for detail work or cutting in confined spaces. Wouldn't use them for cutting off casts, but theoretically you could.
hahaha im gonna try that 🤣
@@ccoder4953 its most commonly called multitool because it has many kind of functions
It's also good at locating prostate cancer, if you weren't aware.
wut? :O how?
I've actually always been wondering about this, but not enough to look it up, thanks for showing this.
I really appreciate how this video is both really great edutainment for myself while just browsing youtube BUT ALSO it can be an incredibly powerful tool for helping people with anxiety about getting their cast removed. Your visuals and story telling are so easy to understand and follow that I believe this video could be fantastic for young kids who might be afraid when they're getting a cast removed. (And honestly probably even adults my age getting their cast removed too :p)
I've had several casts removed in this way. The video still made me nervous though - couldn't watch it all the way through. 🤢
I was 12 and saw the doctor pull one of these out and I feared for my life, he then demonstrated it on his skin to show me it’s safe. The few seconds I spent not knowing that was the most terrified I’ve been in my life.
Except when I was having my cast taken off as a kid, the doctor kept moving it along the cast really fast and ended up cutting me a bunch. I kept saying it hurt and they said "No, it doesn't hurt you". Had scars from that for many years.
That's appalling! Scars both mental and physical I should think. My brother had to be catheterised regularly and he had one nurse who did it badly and he told her she was hurting him and she said "oh everyone says that" YEAH WELL THEN LISTEN TO THE PATIENT maybe?? Man I'm angry for you, I hope you put in an official complaint.
I had the same thing happen to me when I was 7ish, I still have the scar on my leg.
Yep cut me and left a scar from top to bottom of my leg that took years to clear.
I had the exact same experience! It was in second grade, and she cut my arm in 3 different places which ended up getting so badly infected my hand swelled up to the size of a balloon and had to be hospitalized a week later. At first they were convinced I must have been bitten by a spider or something and it wasn't until the second day in the hospital they they realized it was from the infected cuts.
yup same here, broken ankle cast being removed. I said ouch that hurt, lady assured me i was fine. Blood was running down my leg lol
7:52 I think your cast saw is broken. The link you’ve writen on it didn’t get blurred.
Lmao
Plaster of paris is still preferred over fibreglass for a new fracture. I'm not entirely sure why, but I think it has to do with PoP ability to allow the limb to swell without cutting off blood supply. PoP is used excluisively in ED to stabilise fractures before surgery/imaging. The fracture clinic wouild give you a fibreglass cast to replace a PoP cast once the risk of swelling has gone.
0:14 Mistake: those drywall saws are not affiliated, their tips are round...
The first time I saw this difference between solid and squishy things like people, was when I started at an auto parts store. My boss told me to hold this engine part in my hands while he removed a bolt with an impact wrench. I didn't know how it worked and thought it was gonna try rip the part from my hands, and I braced for it to twist hard. He said "No, relax, it doesn't work that way" and torqued the seized bolt right out of it while I wasn't even ready, it just shook a bit and didn't twist at all. It was the coolest thing ever
My little brother had a wicked scar for the longest time from a cast saw that either malfunctioned or was used incompetently by medical staff. I wasn't there but according to the story he was screaming the entire time and the doctor kept telling my mom he was just overreacting until the cast came off.
I cut my son’s cast off with my oscillating saw last summer. It was due to come off and the next available appointment was a couple weeks out. It was pretty fun to remove, and having watched several of my casts being removed previously helped with my technique. We both also wore masks to avoid breathing in the fiberglass dust.
Bro had me on the intro, i thought he cut his arm
The main reason for the cutting ability of this tool is the impedance matching between the blade and the material you're trying to cut. Only if this condition is fulfilled, the impulse and hence energy is successfully transferred to the material. You have the same effect if you leave high frequency coaxial cables open or shorted at the end.
High frequency coaxial cable destruction through impedance matching? That sounds like good video material.
While I may not understand all the math behind your research, I appreciate you breaking down complex scientific questions and make them more consumable for people who are naturally curious about everything in life. Thank you for your hard work.
Hey, Nice vid! Just a small correction, I believe the thing you are measuring is the particle velocity and not the speed of sound in your skin. Particle velocity is dependant on the impact velocity, where as the speed of sound in the material is an intrinsic property of the material, based on the density and stiffness. Also just consider that the speed in sound in air is approx 300 m/s, and this increases with density (e.g. water is approx 1500 m/s), so there is no way that your skin has a speed of sound in the order of 10 m/s.
Great Video Steve! I was always wondering how they make sure to not cut your skin. I think it's kind of funny you mention proprietary batteries on power tools at 6:23, while showing a Bosch driver using the ALL 18V Alliance battery system that aims to make batteries of different manufacturers MORE compatible, thus not being proprietary.
I used to work with these saws in my job and everyone said they don't cut skin but I DID NOT HAVE THE NERVE to test it. Glad to see you prove it first!
I've got an wrist fracture few years ago. Didnt expect this video to pop up in my recommendations. I expected that a cast have a special material that only cast can cut but wasnt expecting that the saw moves quickly at a small distance that cut rough material. Interesting video!
I had casts put on my limbs numerous times in my life and each time when the time came for them to be taken off, I always feared that this time doctor would chop off something important along with the cast. Thank you!
I remember my grandpa pulling out his actual rotating saw, sliding a ruler under my cast and cutting it off…
The cut (lol) from you grimacing and bringing what looks like a rotary tool up to your face, to you half clean-shaven, was hilarous.
This unlocked a memory from kindergarten in 1997 when we had a demonstration of this in class and every kid was scared to try but it was so fascinating!
A point of note about cast materials: plaster of Paris is much heavier than the fibreglass casts, which is why it is preferred for fractures which need to be set for a long(ish) period. However, depending on when you attend A&E, you might still get a plaster cast as a temporary fix until the fracture clinic can get you in to set your break using fibreglass.
Broke my arm as a kid on holiday in France. When it was time to get rid of the cast we visited the local hospital. Was terrified and couldn’t understand a word from what they were saying. This kind lady took the saw, turned it on and before she started to cut the cast, she held the running saw against the palm of her hand. Felt like pure magic…