From bespoke seats to titanium arms, 3D printing is helping Paralympians gain an edge

Jeff Crow/AAP Image

Authors: James Novak, The University of Queensland | Andrew Novak, The University of Technology Sydney

** Please note: this is a copy of an article I wrote for The Conversation, published on 3rd September, 2021, and is shared under a CC-BY-ND license. You can access the original article by clicking here.**

Major sporting events like the Paralympics are a breeding ground for technological innovation. Athletes, coaches, designers, engineers and sports scientists are constantly looking for the next improvement that will give them the edge. Over the past decade, 3D printing has become a tool to drive improvements in sports like running and cycling, and is increasingly used by paralympic athletes.

The Paralympics features athletes with a diverse range of abilities, competing in a wide range of different categories. Many competitors use prosthetics, wheelchairs or other specialised components to enable them to perform at their best.

One interesting question is whether 3D printing widens or narrows the divide between athletes with access to specialised technologies, and those without. To put it another way, does the widespread availability of 3D printers — which can now be found in many homes, schools, universities and makerspaces — help to level the playing field?

Forget mass production

Mass-manufactured equipment, such as gloves, shoes and bicycles, is generally designed to suit typical able-bodied body shapes and playing styles. As such, it may not be suitable for many paralympians. But one-off, bespoke equipment is expensive and time-consuming to produce. This can limit access for some athletes, or require them to come up with their own “do-it-yourself” solutions, which may not be as advanced as professionally produced equipment.

3D printing can deliver bespoke equipment at a more affordable price. Several former paralympians, such as British triathlete Joe Townsend and US track athlete Arielle Rausin, now use 3D printing to create personalised gloves for themselves and their fellow wheelchair athletes. These gloves fit as if they were moulded over the athlete’s hands, and can be printed in different materials for different conditions. For example, Townsend uses stiff materials for maximum performance in competition, and softer gloves for training that are comfortable and less likely to cause injury.

3D-printed gloves are inexpensive, rapidly produced, and can be reprinted whenever they break. Because the design is digital, just like a photo or video, it can be modified based on the athlete’s feedback, or even sent to the nearest 3D printer when parts are urgently needed.


Read more: Paralympians still don’t get the kind of media attention they deserve as elite athletes


Harder, better, faster, stronger

An elite athlete might be concerned about whether 3D-printed parts will be strong enough to withstand the required performance demands. Fortunately, materials for 3D printing have come a long way, with many 3D printing companies developing their own formulas to suit applications in various industries – from medical to aerospace.

Back in 2016, we saw the first 3D-printed prosthetic leg used in the Paralympics by German track cyclist Denise Schindler. Made of polycarbonate, it was lighter than her previous carbon-fibre prosthetic, but just as strong and better-fitting.

With research showing sprint cyclists can generate more than 1,000 Newtons of force during acceleration (the same force you would feel if a 100-kilogram person were to stand on top of you!), such prosthetics need to be incredibly strong and durable. Schindler’s helped her win a bronze medal at the Tokyo games.

Denise Schindler on her way to a medal in Tokyo. Thomas Lovelock

More advanced materials being 3D printed for Paralympic equipment include carbon fibre, with Townsend using it to produce the perfect crank arms for his handbike. 3D printing allows reinforced carbon fibre to be placed exactly where it is needed to improve the stiffness of a part, while remaining lightweight. This results in a better-performing part than one made from aluminium.

3D-printed titanium is also being used for custom prosthetic arms, such as those that allow New Zealand paralympian Anna Grimaldi to securely grip 50kg weights, in a way a standard prosthetic couldn’t achieve.

Different technologies working together

For 3D printing to deliver maximum results, it needs to be used in conjunction with other technologies. For example, 3D scanning is often an important part of the design process, using a collection of photographs, or dedicated 3D scanners, to digitise part of an athlete’s body.

Such technology has been used to 3D-scan a seat mould for Australian wheelchair tennis champion Dylan Alcott, allowing engineers to manufacture a seat that gives him maximum comfort, stability and performance.

3D scanning was also used to create the perfect-fitting grip for Australian archer Taymon Kenton-Smith, who was born with a partial left hand. The grip was then 3D-printed in both hard and soft materials at the Australian Institute of Sport, providing a more reliable bow grip with shock-absorbing abilities. If the grip breaks, an identical one can be easily reprinted, rather than relying on someone to hand-craft a new one that might have slight variations and take a long time to produce.


Read more: 3 reasons why Paralympic powerlifters shift seemingly impossible weights


All these technologies are increasingly accessible, meaning more non-elite athletes can experiment with unique parts. Amateurs and professionals alike can already buy running shoes with 3D-printed soles, and 3D-printed custom bike frames. For those with access to their own 3D printer, surf finscycling accessories and more can be downloaded for free and printed for just a few dollars.

However, don’t expect your home 3D printer to be making titanium parts anytime soon. While the technology is levelling the playing field to a certain extent, elite athletes still have access to specialised materials and engineering expertise, giving them the technological edge.


This article was co-authored by Julian Chua, a sports technology consultant at ReEngineering Labs and author of the Sports Technology Blog.

3D Printing in Sport – Hit or Hype?

If you’re into 3D printing, no doubt you are familiar with some of the ways it is being used in sports. Some of my own products (above) have included a 3D printed bicycle frame, smart bicycle helmet and surf fins, while in the media products have included shoes, golf clubs and shin pads.

However, as a researcher, I was interested to know how this translates into academic research. How many research studies have been looking at 3D printing for sports products? How much improvement does a 3D printed product offer over a conventional one? Which sports are adopting 3D printing? Working with my brother, Dr Andrew Novak, we hypothesized that given the amount of coverage in 3D printing media, there should be quite a large amount of research supporting the developments of iconic 3D printed sports products, as well as novel developments that haven’t even made it into the media yet. The results – published in a paper titled ‘Is additive manufacturing improving performance in Sports? A systematic review‘ – were surprising (preprint version freely available).

Up until May 2019, we found only 26 academic studies that provided any empirical evidence related to 3D printing for sports products. The graph above shows which sports, and how many articles have been published. The first of these appeared in 2010. Running/walking was the most popular sport with 10 articles (38%), followed by cycling with 4 articles (15%) and badminton with 3 articles (12%). All other sports – baseball, climbing, cricket, football (soccer), golf, hurling, in-line skating, rowing and surfing – had only been assessed in single studies. This means that a lot of research into 3D printing of sports products are just one-off projects, and indicates that there may be very little funding/interest to continue building larger projects.

It also suggests that any research being done to support mainstream commercial applications of 3D printing, for example for brands like Adidas and Specialized, is protected by intellectual property (IP) and not being published.

10 articles (38%) observed improvements in performance of products developed via 3D printing compared to conventionally manufactured products, 8 articles (31%) found a similar performance, and 5 articles (19%) found a lower performance.

From a technical perspective, powder bed fusion technologies were the most utilized with 50% of articles using either selective laser sintering (SLS) or selective laser melting (SLM), although 52% of articles did not name the 3D printer used and 36% did not name any software used to design or optimize products. 3D scanning technology was also utilized in 11 articles (42%).

So, is 3D printing in sport a hit or hype? Based on this research it is clear that within academia, 3D printing is still in the very early phases of consideration, and seems to be significantly behind industry. While you may be able to go and buy some 3D printed running shoes or insoles, or cycle on a 3D printed saddle, you won’t find any objective data in journal articles on these products or much research to suggest that 3D printed products are any better than conventionally manufacture products.

– Posted by James Novak

Customising Surf Fins for 3D Printing

Early followers of this blog may be familiar with several projects to 3D print kiteboard and stand up paddle (SUP) board fins, including some fins you can freely download if you’re into kitesurfing. It’s been a little while between posts on this topic, however, I have been busy in the background producing a system to help people with no CAD experience design and customise their own fins ready for 3D printing. The full details have just been published in the Computer-Aided Design and Applications Journal.

Quite a few people have used 3D printing to produce surf fins – after all, it’s very cheap and means you can produce just about any geometry you like. Researchers have looked at the strength of different materials and 3D printing technologies for this application, as well as the performance (fluid dynamics) of different geometries. However, if you are not a relatively advanced CAD user, it is unlikely you will be able to design the fin of your dreams, no matter how awesome the research suggests 3D printing can be! This is what I was interested in solving.

Using Rhinoceros and Grasshopper, the complexity of a fin was condensed down to a series of limited controls that allowed for freeform experimentation. The above image is the interface that allows surfers to customise a fin design in real-time. It is based on a handful of common fin properties such as the fin system, fin position on the board, cant, fin depth, sweep, base length, base foil profile, tip sharpness and tip thickness, all of which can be modified using some simple sliders or dropdown menus. Feedback is also provided in the form of overall dimensions and volume. From the image at the top of the page, you can get a sense for the wide variation in designs possible from this simple interface.

Once you’re happy with the design it can be exported ready for 3D printing. I’ve 3D printed a couple of different designs for testing on my SUP board, the smaller white fin in the image above being 3D printed using FDM, while the larger fin was 3D printed using selective laser sintering (SLS). Both worked well in flat water paddling, although I’m sure some carbon fibre would give me a bit more confidence heading into the surf.

Hopefully some more to come soon as spring and summer approach.

– Posted by James Novak