#prosthetics

Now look, I get why people want to draw these on their amputee and limb different characters, they look cool as hell AND they make you fast! I pestered my prosthetist for years to let me get a pair, admittedly, mostly because of the aesthetic so trust me, I get it.

But running blades are made to run, and only to run. Sometimes to jump, but mainly to run. You see, running blades look the way they do, because they aren't actually based off of human anatomy at all. The original running blade was inspired by the hind-legs of animals like cheetahs, dogs and other fast-moving land mammals. As the furries among us would already know, a lot of these animals have something called digitigrade legs, meaning they don't stand with their entire back foot on the ground. What we see as their paws is actually just the ends of their toes, and their ankle is held up off the ground. The reason so many animal species evolved with this trait is because it makes you really fast (among other things). The entire leg essentially works like a spring, giving the animal more force to push themselves forward, at the cost of the limb being a little less stable to stand on. that isn't an issue when you have another two legs out in front, but it's part of the reason why you don't see many bipedal creatures in nature with digitigrade legs.

Running blades took this general digitigrade leg layout and kind of simplified it, functionally making the athletes run on their toes. The blades are made out of very strong and very flexible carbon fibre sheets, and when the "toe" of the blade hits the ground, the force of the impact causes the whole blade to bend, then rebound, using the runner's own force and momentum to push them forward again. However, unlike most animals, humans don't have another set of legs out in front to keep us stable, so when the person with the blade prosthetic stops running, they either become very unstable or will fall over. This is because, in order to get that spring-like motion, these prosthetics can't have a heel and the way our body's weight is distributed means we kind of need that. Some leg amputees are able to walk a little bit in these running blades, but its not easy and is generally pretty uncomfortable to do, and for double leg amputees, it's exceptionally difficult.

There's also the fact that the running blades need a lot of force applied to them to actually work. A friend of mine brought her blade to an event we were both at, and you could not get the arch of the blade to bend with your arms. At all. One of the other guys at the event was a Paralympic powerlifter, and even he couldn't do it. even leaning on it with all our body weight wasn't enough to make it bend and push back. The only way to get it to bend was by landing on it while running at full speed - which is no small amount of force. Anything less and it won't budge, making these essentially very poorly balanced peg legs when used for anything other than running and jumping. This was actually the reason my prosthetist never signed off on me getting a pair of running legs, because I had an issue that made my stumps too sensitive to withstand the forces needed for them to work properly.

So unless your amputee character is going to be running everywhere at a full sprint, they don't need and probably won't benefit much from having blades in place of a regular prosthetic foot. However, if you want some extra speed for your amputee character, without the significant balance issues that come with a blade, hybrid feet do exist! These hybrids are made out of the same carbon fibre sheets as the big blades, but are shaped more like a regular leg and ankle, with an additional piece attached to the back to give you the stability of having a heel. These hybrid feet, often called active feet or high-mobility feet, take the best of both kinds of prosthetic, while also allowing their user to wear shoes, thanks to the rubber foot shell that goes over the top. They aren't as great for running as the big blades, but they're a lot better than most other prosthetic feet.

The one exception to all of this is if your amputee or limb different character isn't actually human. Quadrupedal mammals like dogs and cats who have their hind legs amputated often get something that looks like a running blade prosthetic as the shape mimics what they'd naturally have without the need for expensive (and completely impractical for animals) electronic parts. When it comes to furry and anthropomorphic animals, I personally make an exception here as well. Technically, the same rule should apply; they're bipedal, so they shouldn't be able to easily stand on a running blade and it wouldn't be practical. However, that rule should also apply to any furry with digitigrade legs, they should be equally unbalanced on their natural meat legs because that kind of bone structure isn't great for a bipedal creature, but it's just kind of an accepted thing to ignore that within the furry community, as long as you can make it look good. In this case, a running blade is the closest a digitigrade furry could probably come to a functional prosthetic without robotics, so I'm more inclined to let it go in that case.

Sports wheelchairs

The wheelchairs used in basketball, tennis and rugby are all different, but the features I see getting used in character designs are, for the most part, in all three, so for the sake of simplicity, going forward I'm going to refer to them all collectively as sports chairs. "Sports wheelchair" is an umbrella term that encompasses a lot more than just these three types, but I don't think I've seen anyone confuse a racing or golfing wheelchair for a general use wheelchair, so for this article, I'm mainly going to be using it to refer to those three. Likewise, going forward, I'm going to be calling normal, non-sports wheelchairs "day-chairs," which was a popular way of shortening "daily-use wheelchair" when I played wheelchair sports.

Just like the running prosthetic, sports wheelchairs are made to do one thing very well, and only that one thing, which is why people who play wheelchair sports of any kind need to have an entirely separate wheelchair to play in. The wheelchairs designed for Rugby and basketball are made to go on perfectly flat, perfectly smooth, indoor basketball courts. Likewise, tennis chairs are made to play on perfectly flat and smooth tennis courts. But it's pretty hard to find anything that smooth and flat outside of those specific spaces and these chairs don't handle any other type of environment well at all, even including the entrances and exists to the courts. These sports chairs are so bad at dealing with anything else, in fact, that people who play these sports will usually stay in their day-chairs, right up until they're on the court's sideline, then swap into the sports chair only when needed.

This is because the features that make these wheelchairs so good for their respective sports, tend to cause a lot of logistical problems anywhere else. For example, when most people think about sports wheelchairs, one of the first things that comes to mind is probably the big, tilted wheels. The wheels on all sports chairs are angled outwards, with the wheels closer at the top, and wider at the bottom - this is called wheel camber. A standard day-chair, though, usually has no, or very little camber - wheels that are not tilted outwards. Giving sports chairs camber has a lot of benefits, with the main one being added stability. When you're playing a game like wheelchair basketball or rugby, which are contact sports, you need to be able to take a hit without falling over, and a wider base of support helps with that a lot. The larger wheels on these chairs also tend to sit pretty far forward, which shifts the chair's centre of gravity, making it way easier to do precise, tight turns. However, this makes the chair much less stable, which the camber also helps with, which is one of the big reasons you see tilted wheels on tennis chairs too. Finally, you also need your hands and fingers on the wheels to move, but if someone crashes into you, having the wheels tilted this way keeps your hands out of the way of being crushed on impact...usually.

As you can see, this feature has a lot of advantages, but you'll notice that having the wheels tilted also makes the chair very wide. So wide that they don't actually fit most doors, except double doors. When I played basketball, to even get our sports wheelchairs inside the courts we practiced on, which only had standard, single doors for some reason, we had to sit in our day chairs and push the basketball chairs in front of us with the big wheels removed, or they wouldn't be able to fit inside. I'm sure you can see now why this makes these wheelchairs impractical for daily use. It's hard enough getting a normal day-chair through some building's doors, let alone through crowded or tight places like shops with narrow isles or down narrow footpaths. You will occasionally see a day-chair with a very minor tilt on their big wheels, but it's usually only done on very thin chairs with active or experienced users, and it's almost never more than a 2 - 5° tilt (whereas sports chairs can have as much as 15° to 20°, depending on the sport).

But tilted wheels aren't the only thing that makes them impractical for daily use. Another feature of these chairs is their anti-tip wheels; little wheels at the back that stop you from falling backwards out of your chair. A lot of day-chairs have anti-tips too, but the ones on day-chairs are usually positioned so that the wheelchair can still be tilted back enough to get up things like curbs and small steps and mildly rough terrain. However, remember how I said sports chairs have their big wheels moved further forward to help them turn easier? this will cause the chair to tip back way easier, and to account for that, the anti-tip wheels on sports chairs have to be basically touching the ground. If they weren't, every time you pushed forward, you would loose a bunch of your energy and momentum from tipping back slightly. You'd also probably damage the courts after a while too from forcibly slamming your front and anti-tip wheels into the ground repetitively. So they make the anti-tip wheels as close to the ground as practically possible to stop that, and also so you can lean as far back in the chair as you need, without having to worry about falling back but this means the chair is prone to getting stuck on everything and anything if the ground isn't perfectly flat and smooth. Even trying to take one of these chairs down a tiny curb-cut ramp is likely to result in your front wheels getting wedged on the road, while the anti-tips get stuck on the ramp with your big wheels (the ones you use to propel yourself forward) getting stuck in the air.

Finally, there's also the size. Even without tilted wheels, these chairs are often quite a decent bit larger than a day chair, mostly to protect their user. Most sports wheelchairs have a protective bar in front and around the sides of the chair, and the anti-tips add quite a bit of extra length to them in a lot of cases. The bar protects your feet in the event of a collision or fall, and makes the chairs more bottom-heavy to prevent them from tipping over whenever you make a sharp turn, and the anti-tip wheels need to extend a decent way out of the back of the chair or else they can't do their job. These things don't matter too much on the court, but once again, out in the real world, it makes a big difference.

There are a few other little differences too that can, in some cases, make them less practical. things like the fact breaks are never included on sports chairs (anymore) because they just weren't needed during the games and increased the risk of hand injuries - I lost a few thumbnails from snagging them on my day-chair's breaks when I was pushing fast. Sports chairs also can't fold down, as making them able to do so is a safety hazard since it weakens the frame of the chair. So that, combined with their larger shape means they can really only be transported by most people by putting them in the back trunk of the car, whereas even day-chairs that can't fold are designed to be able to be placed on a car seat, meaning they're easier to get in and out of a car when you don't have anyone to help you.

I speak about all of this from experience, by the way. As a teenager, my first wheelchair basketball coach intentionally didn't explain the above points to me when he lent me my first ever sports wheelchair. He knew the first thing I was going to do was try to take it to school, and he knew I wouldn't listen if he just told me not to try it, so it was just better to let me figure it out on my own. My old English classroom's door still has a big chunk of paint missing from where I tried to force this extra-wide sports chair through almost 10 years later, and I was late to every single class that day because the school's elevator had a small lip by the door I kept getting stuck on. Not to mention the several times I got stuck on the curb cut just trying to leave our local courts the day he gave it to me.

Sometimes kids just have to learn through trial and error, and I definitely tried, which is why it's so funny to me when I see wheelchair using characters in fiction either using just a straight-up sports wheelchair as a day-chair, or who's day-chair was designed by someone who very clearly just googled "cool/sporty/fast wheelchair" and slapped a bunch of features they saw onto a more standard wheelchair without understanding what those things actually do.

Conclusion