Engineering excellence in ski touring: a parallel to medical device design
Published: March 2025
Will Davies, Design Consultant
Continuing our exploration of the inspiration of personal interests and passions on medical device design at Shore, we shift our attention from the parallels between Grant’s mountaineering and user experience to a discussion with Design Consultant, Will.
What's your passion?
Personally, nothing quite removes me from the burdens of everyday life like the exhilaration of alpine ski touring. For the uninitiated, this is not driving between resorts; ski touring is about using dedicated skis, bindings, and boots (amongst various other bits of kit) to enable efficient travel across snow – both up and downhill – and the promise of an untracked world of powder-filled mountain adventures.
The origins of ski touring are ancient. Someone somewhere snowy once stuck some seal skin to their rudimentary skis, noting that the directional hairs of the skin enabled smooth forward sliding and backward grip on the snow. Today, synthetic materials replace seal skin, but the principle endures and remains the foundation of the sport.
Which piece of ski touring gear do you admire most from an engineering perspective?
It’s the technical challenge, innovation, and engineering rigour of the bindings that never cease to inspire me in my work. Originating from Nordic skiing, in which the toe of the boot is fixed to the ski but the heel lifts free to permit a walking action (skinning), there is now a myriad of different touring binding options available. These have developed through a rapid process of engineering evolution and innovation in which the basic premise has developed and diverged to fill all niches of the off-piste skiing market – from multi-week expeditions to shredding down near-vertical couloirs – and satisfying the often-conflicting demands of light weight, performance, reliability, and cost.
Fundamentally, a touring binding differs from a cross-country binding in that the boot is allowed to pivot about the toe for going uphill, but then the heel is locked down firmly for the descent to allow conventional alpine ski technique. This presents two key challenges: firstly, when in uphill mode, the binding must not release from the boot. Any detachment of a ski from a boot would be at least frustrating and at worst catastrophic when ascending a crevassed glacier or a steep mountainside. Secondly, when in downhill mode, to prevent injury the ski must release from the boot under certain load conditions (i.e. wipeout). A ski is potentially a very long lever applying some serious torque to the knee if it doesn’t come off the boot. Invariably there are some grey areas in both of those demands where the opposite behaviour might be required (don’t fall here!!), which just adds to the engineering challenge.
Have there been any advancements made?
Traditional alpine touring bindings took a standard alpine downhill binding and stuck it on a frame, pivoting at the front against the ski. These designs were reliable and safe but heavy. Then, in the 1980s, a company called Dynafit shook up the market, introducing the pin binding. This was a radical reinvention which saw the toe and heel bindings mounted directly to the ski, saving as much as a kilo per foot – a very significant amount when shuffling skis uphill all day long. This required a dedicated boot design: the toe binding has two metal pins that pop into sockets on each side of the tip of the boot sole, providing the pivot. At the heel, two sprung metal pins lock into sockets; these pins are disengaged for uphill travel and re-engaged for downhill shredding.
The challenge with this design is how to control the release manner and forces. The heel binding pins are a single metal rod formed in a U-shape, with the two arms of the U flexing apart to allow it to engage and disengage with the boot. The U-shaped rod is itself a clever bit of engineering, with its diameter changing along its length to create the desired spring characteristics. A screw dial pushes a limiter along the arms of the U to increase or decrease the bending moment and hence the spring force in line with DiN settings, so the release point can be tuned according to the skier’s weight and skiing style. Very simple, very clever, very light, and so far, so good.
The real challenge lies in the design of the toe binding. The inward-closing pins rely on a vertical boot movement to engage and disengage, using strong springs and an over-centre action to flick from one state to the other. This means that in the event of a crash where the ski rotates upon its plane without any vertical movement, the toe binding won’t release, potentially resulting in serious knee injury. Not ideal halfway down a mountain.
Enter the engineers. Recognising this issue but unwilling to compromise the performance fundamentals of the binding, recent models allow the whole of the toe binding to rotate a little upon the ski. In a rotational crash, this enables the heel binding to pop out, which then permits the toe to release as the ski becomes unconstrained. In hard skiing, it also permits the ski to flex a little underneath the boot, allowing front-to-rear binding misalignment without premature release – an often hilarious but potentially serious occurrence.
How does the toe binding not release when in skinning mode? A lever at the front of the toe binding is pulled upwards, which locks the pins into the engaged position with varying degrees of security; pull hard for extra reassurance on those dawn starts from the hut when your steep ascent route is still bullet-hard ice.
So – some very clever design and engineering then, which has given me so many hours and metres of good times (and spectacular crashes – I’m no expert). But what’s more, all this cleverness is arranged in such a small and lightweight package that it’s quite incredible how well it all works; a great example of something that at first glance appears to be simple, hides some exquisitely complex and well-considered engineering detail to provide reliable function in an extremely demanding and dynamic environment.
How does this relate to your work in medical device design?
I find that hugely inspiring in my own work as a product designer – if something so minimalist can function so effectively under such demanding load conditions, then anything is possible. It has made me recognise many parallels between high-end ski equipment design and medical device design: for instance, reliability is essential – potentially life-critical – and so every aspect must be tested and refined again and again to iron out weaknesses.
Function is similarly paramount – just as a skier cannot afford to be let down by equipment at 4000m, a drug delivery device must also work perfectly every time. Lightweight yet still robust? A good parallel here is with the patient’s desire to have a medical device – such as a wearable injector – be as small and discreet as possible, whilst still working flawlessly and putting up with the rigours of life.
Finally – skiing is a passion, and all skiers want their kit to look good and be easy to use; in contrast, use of a medical device is born out of necessity, but great aesthetics lead to user acceptance; and good ergonomic, UI and UX design ensures efficiency and ease of use – all of which create a competitive edge and increase brand loyalty.
What inspiration or appreciation do other designers and engineers get from the kit that facilitates their passions? See more from the team in the links below, along with more insights from Will.
