As 3D printing becomes more widely available, it’s becoming more approachable to design and create custom fitting medical braces without the need for specialized training or equipment. With this project, I set out to do just that.
I’m a PC gamer, I use a “claw” grip on my mouse, and my fingers are double jointed. That particular trio doesn’t usually cause a problem, but when I’ve been at my PC for a few hours, my finger joints get fatigued and my mouse grip devolves into something else entirely.
Once I’ve reached this point, my fingers get painful to curl, and can lock and click, and that even continues when I’m no longer at my computer. Ouch!
Prior to taking on this project, I had already figured out a few ways to address the problem, but none of them were great. I could tape up my fingers like a boxer would, which was actually very effective, but I could seldom be bothered with the hassle of it. I could also make a conscious effort to grip the mouse differently, but that’s not a great solution either, since it’s not natural for me. What I needed was something that would keep my fingers from bending the wrong way at the first joint.
Using OpenSCAD, I put together the first design.
The first design was quick to implement, using a couple cylinders and a cube to join them, but it was obvious that there were problems with it. The strip of plastic holding the rings together was likely going to be too fragile, the sharp edges on the rings would make the brace uncomfortable to wear, and the odd angles around where the rings joined would’ve printed poorly. I toyed with the design a bit more, but ultimately, there wasn’t much improvement to be made with the direction I had gone. Time to start over.
This time I started with the idea of what a jewelry ring would look like, and went from there. Using an oval to set up the cross-section of the ring, I used rotate-extrude to flesh out the ring shape. I also beefed up the weld, opting for a cylinder to join the rings rather than a cube. Before long, it was time to print.
The first try didn’t stick to the hot bed, so that attempt was scrapped almost right away. The second and third tries finished successfully, but due to the small size of the brace, the upper layers didn’t have time cool before the next was added, and the end result was goopy and stringy. Ultimately, the solution was to print four rings at once, which gave the plastic plenty of time to cool between layers. With a little sanding to fit, and a bit of nail polish remover to give the ABS a nice finish, the best ring was ready to try out.
It works! As an added surprise, I only needed one brace to solve the problem on that whole hand, since my fingers only bent the wrong way as a group. They wouldn’t do that with the middle finger braced. I decided to break one of the spares, both to find out where to expect the plastic to fail, as well as to get an idea of how durable the brace would be in the long run.
The ring was stronger than I had expected, and it’s clear it would be very unlikely to break under normal use. To make things even better, since the brace is 3D printed, I could simply heat up the broken ends of the ring with a lighter and stick them back together!
While the finger brace is effective, reasonably comfortable, and quite durable, there is some room for improvement.
Even though I took measurements of my fingers to make sure I’d get a good fit, I hadn’t taken into account that the rings wouldn’t sit level, so they ended up a bit snug. Another issue with the rings being at angles is that they create pinch points along the top of the finger when I straighten it. Luckily it’s not too bad, and even so it doesn’t come into play at all when I’m using a mouse.
Overall I’m pleased with the result, and even a couple weeks later, I still use it on a daily basis. I expect to continue using it for quite some time. The brace design is now available on Thingiverse. Not surprisingly, there’s nothing else like it.