Ensuring that a ski boot supports the foot evenly is key to accurately transferring movements and forces to the ski. When pressure is concentrated too much on certain points, this can lead to pain, numbness and a loss of comfort; when there is too much slack, the foot moves around inside the shell, reducing control and potentially increasing strain on certain joints. So far, nothing new.
For years, the main selling point of the BOA system in ski boots was simple: to offer a more precise fit. Now the company wants to go one step further and demonstrate that the way a boot wraps around and supports the foot can also influence power transfer, stability and control. Its Human Performance Fit Lab has been measuring these variables for eight years. The next frontier will be to see to what extent this technology ultimately makes inroads into the last territory where traditional buckles still reign supreme: the boots of World Cup racers.
Any skier with a bit of experience will recognise the scenario: you put on your boots, which are a bit loose, get on the first ski lift and, just before the first run of the morning, with your boots still cold, the doubt creeps in: should I tighten them as much as possible or just a little?
If they’re too loose, your foot will slip around. If they’re too tight, after a few runs down the slopes you’ll start to feel pressure on the instep, a tingling sensation, numb toes or even pain caused by your ski boots.
For decades, we have accepted this constant adjustment as part and parcel of skiing. The boot needs to hold the foot firmly in place because it has to transfer our movements to the ski, but that very pressure can become a source of discomfort, and the BOA system aims to show that this does not necessarily have to be the case.
The US company, which will celebrate its 25th anniversary in 2026, has just published the first impact report from its Human Performance Fit Lab (HPFL), the laboratory through which it aims to scientifically measure the extent to which the way the foot is secured can influence not only comfort but also performance. And some of the figures provided in its press release have caught our attention.
In alpine skiing, BOA claims to deliver up to a 6 per cent improvement in power transfer, a 10 per cent improvement in stability and control, a reduction of up to 14 per cent in peak pressure on the instep, and time differences of up to 0.45 seconds in competition runs. But behind those figures, one thing stands out: securing the foot more effectively isn’t simply a matter of tightening the boot more, but of distributing the pressure more evenly across the entire surface of the foot.
However, it is worth remembering that the fastening system is still only one part of a boot’s fit. The size, last, foot volume, liner, flex and boot-fitting process remain key factors. A perfectly adjusted BOA cannot compensate for a boot whose geometry does not match the skier’s foot.
From a wheel that replaced buckles to the study of biomechanics
BOA was founded in 2001 and claims to have served around 300 million users since then. For much of its history, the pitch was fairly straightforward:
“to replace certain lacing or fastening systems with a dial capable of providing small increments of tension.”
But in 2018, the company set up its Human Performance Fit Lab and began to study not only its fastening system, but also the relationship between the foot, footwear and human movement.
Eight years on, BOA claims to have accumulated more than 17,000 million data points, carried out more than 1,871 tests with athletes and professionals, and participated in the development of more than 645 product solutions with its partner brands. It also claims to have published six peer-reviewed technical papers.
And all these laboratory analyses and real-world tests were aimed at achieving multiple objectives. The aim was to try to measure what happens when an athlete turns, accelerates, lands, pushes off or changes direction: where the pressure is applied, when the force is generated, how long it takes for that force to be transmitted, and how much movement occurs within the shoe.
In skiing, where the boot is practically the only mechanical link between our body and the skis, this measurement seems to make a lot of sense.
What actually changes inside a ski boot?
A traditional ski boot uses several buckles to tighten and compress the shell around the foot. These are the classic ones. The BOA system works differently. A cable runs through different points on the shell and, when you turn the dial, it gradually increases the tension around the foot, changing the way the pressure is distributed.
In some of the best BOA ski boots, we can see that the very architecture of the boot has been redesigned. HEAD uses a dual-injection moulded shell in its Kaliber model, with stiffer plastics in the power transmission zones and more flexible materials over the forefoot; K2 also uses different grades of thermoplastic polyurethane (TPU) depending on the function of each area of the shell; and Salomon has developed its ExoDrive with reinforcements, additional layers of polyurethane and an offset pivot to work in conjunction with the BOA closure system.
The BOA report shows in the image above a comparison of the pressure maps obtained from a boot fitted with BOA and another with a traditional fastening system. The illustration is visually very telling: in the buckle configuration, areas of higher pressure are concentrated at specific points on the instep, whilst with BOA the pressure is distributed more evenly. It is important, however, not to interpret the graph as suggesting that a BOA boot automatically fits the foot ‘like a glove’. It is the result of a specific configuration and testing protocol, and the fastening system is just one of the variables that determine the fit.
Good boot fitting aims precisely to achieve that very objective of distributing pressure more evenly:
“Choose a last that fits the foot properly, thermoform the upper and, where necessary, make localised adjustments to the shell to resolve problem areas.”
The difference is that BOA aims to facilitate this distribution through the very design and operation of the fastening system, whilst also allowing it to be progressively adjusted whilst the boot is in use.
In short, BOA focuses on how the boot fastens and on boot fitting – in other words, how the boot adapts to the foot. These are two distinct and potentially complementary areas of work. From our point of view, the starting point remains that the boot has the correct geometry for that foot.
22 skiers and two almost identical pairs of boots
In 2023, a study was published in Frontiers in Sports and Active Living comparing two versions of the same Salomon S/Pro Supra Max 120. The main difference lay in the lower shell’s fastening system: one used BOA and the other buckles. Initially, 22 skiers took part, and during the runs, plantar pressure sensors and inertial measurement units were used to study what happened during turns. The researchers sought to objectively measure how the skiers’ behaviour changed; however, the sample is not representative of the entire market: the participants were men, expert skiers and accustomed to carving. The study does not reveal whether the same effects would be of the same magnitude in children, women, beginners, lighter skiers or those with very different foot shapes.
Apart from these details, which we consider worth bearing in mind, the participants rated the BOA setup more highly in terms of aspects such as carving, confidence and overall fit. Differences were also observed in the force exerted on the skis and the speed at which that force was applied. But there is one particularly interesting finding:
“No significant differences were found in the edge angle.”
In other words, BOA did not cause the skier to lean more heavily onto the ski; rather, the difference lay primarily in how the force was transmitted. Let’s explain this.
The study detected not only greater force, but a faster application of that force. With BOA, skiers reached peak load on the outside ski sooner, a particularly relevant finding in carving, where the speed at which pressure builds up on the edge determines the initiation and progression of the turn.
More power without pressing the accelerator any harder
A boot that is too tight may provide a feeling of precision, but it can also create areas of intense pressure; indeed, excessive compression on the instep may even restrict blood circulation and contribute to the so-called “cold leg phenomenon”, that is, a drop in temperature associated with the compression of the boot.
The study itself highlights something we’ve all experienced to some extent on a skiing holiday: rigid boots can generate enough pressure to affect blood circulation in the foot and cause numbness. However, the wraparound design studied produced a more even distribution of pressure.
And the Human Performance Fit Lab’s 2026 report summarises the findings with a rather significant figure:
“Up to 14 per cent less pressure on the top of the foot.
BOA associates this configuration with improvements of up to 6 per cent in power transfer and 10 per cent in stability and control within its various test protocols. Furthermore, the study recorded a 12 per cent reduction in average pressure on the instep and a 15 per cent reduction in the variability of that pressure. In other words, the main difference is that the BOA system managed to distribute the load more evenly. And here it is worth clarifying something: these percentages do not mean that any skier will automatically gain 6 per cent in power or 10 per cent in control simply by swapping their buckles for the BOA system.
These results were obtained using specific protocols and set-ups, which is why we at I Love Ski have reached a consensus: actual performance will also depend on the boot, the foot, the skier’s ability, the snow and the skier themselves.
What about those famous 0.45 seconds?
BOA claims to have recorded improvements of up to 0.45 seconds in high-level competition runs. Since the publication of the initial study, the company says it has analysed more than 200 runs with European Cup and World Cup racers (not in official competition heats) to continue assessing its configurations under high-performance conditions.
“BOA is clearly trying to make the leap from commercial products and elite testing into pure alpine racing, but the classic buckle fastening system still dominates World Cup racing boots.”
Salomon’s 2026/27 racing catalogue, for example, retains its S/PRO Race 140 with four buckles, whilst introducing BOA to the S/PRO Alpha C 130 models within the competition range. On the other hand, for the recreational skier, it is probably more important to ensure that the foot remains stable inside the boot without all the pressure being concentrated on just two or three points – which can end up causing pain and a lack of power transfer if the boot is not properly fitted by a professional.
The next step is the DUAL DIAL: two BOA systems in a single boot
Current developments in boots also introduce a significant difference compared with earlier generations. We are no longer simply talking about replacing the two lower buckles with a dial. Dual BOA models, such as the one we tested, allow you to adjust two parts of the boot independently. The biomechanical logic is clearly illustrated in the report.
- At the bottom, the fastening on the shell is designed to secure the heel and connect the midfoot, thereby enhancing power transfer to the ski.
- At the top, the closure of the shank plays a part in controlling the leg and transferring power from one side to the other.
These are two distinct functions, so it makes sense to be able to adjust them independently. We are moving away from a boot where the pressure is adjusted at four points using four buckles towards systems that aim to control entire areas of the foot and the tibia/fibula.
BOA is also looking into snowboarding and cross-country skiing
The same principle applies to snowboarding. In this case, it is particularly important to ensure that the heel does not lift up inside the boot when the rider applies force to one side.
BOA began specifically researching the relationship between fit, biomechanics and carving in snowboarding in 2021 and, based on that data, developed its PerformFit Wrap system.
The 2026 report attributes improvements of up to 3 per cent in speed, 4.5 per cent in power transfer and 9 per cent in stability and control to this configuration, as well as up to 5 per cent greater heel retention during turns on the balls of the feet.
Once again, the same principle applies to snowboarding: limiting the small movements that occur inside the boot in order to convert the rider’s movement more effectively into action on the board.
Although perhaps the most innovative section of the report is cross-country skiing, given that the logic in this sport is somewhat different. In alpine skiing, we essentially aim to transfer force to the skis and control the edges. In cross-country skiing, every slight loss of movement between the foot and the boot can result in energy that fails to be converted into propulsion.
BOA has carried out preliminary roller-skiing trials with athletes from the World Cup, European Cup and NCAA Division I. When comparing the same boot fitted with PerformFit Wrap and traditional laces, the company reports an improvement of up to 2 per cent in heel retention.
This percentage may seem small, but in a sport based on repeating the cycle of push and glide thousands of times, even small differences can prove significant, especially in competition.
92 medals in Milano-Cortina: a figure that needs to be interpreted carefully
At the 2026 Milan-Cortina Olympic Games, athletes using products featuring BOA technology from Atomic, Fischer, Madshus, Salomon and Rossignol won 92 medals: 32 gold, 27 silver and 33 bronze.
The data shows just how deeply BOA has penetrated the equipment used at the very highest level, but, quite frankly, this does not prove that those athletes won because of BOA.
It would be just as wrong to attribute a medal to the binding system as it would be to attribute it solely to the skis, the bindings or the coach. The truth is, quite clearly, that the result depends on a multitude of variables.
However, we find this figure interesting for another reason: a technology that, until relatively recently, seemed to be reserved mainly for beginners, snowboarding or outdoor activities is now making a strong entry into various competitive snow sports.
A BOA investigation which we do not question, but which we must put into context
The 2023 study on alpine skiing was published in a scientific journal and is indexed in PubMed. However, its three authors are affiliated with BOA Technology’s Performance Fit Laboratory, and the research received funding from BOA. The publication transparently discloses this relationship. This does not invalidate the results, but it does mean that they should be interpreted in context.
The sample of 22 skiers remains relatively small, and it would be particularly interesting to see, in future, fully independent studies that replicate the experiments with a larger number of participants, different technical levels, different foot morphologies and different boot models.
BOA itself explains that it publishes its methods and seeks external scientific review precisely in order to subject its conclusions to scrutiny by researchers and laboratories in the sector. Indeed, BOA has already taken its technology from commercial product to testing with elite skiers. The next frontier is pure alpine competition, where the classic buckle fastening system continues to dominate World Cup race boots.
Finally, we must address the issue of micro-adjustment, as it also has its drawbacks. A buckle makes it easy to set a specific position, whereas with a continuous dial, you have to find the right level of tension again. We also recall when we tested the Dual BOA ski boots that they can feel stiff, making it harder to put them on and take them off, especially when the plastic is very cold.
Durability has been another recurring concern amongst skiers accustomed to buckles, although in our view this is largely unfounded. The current alpine platform uses steel cables and components specifically designed for the loads placed on a ski boot, and BOA offers replacement kits for the cable and dial. That does not make the system unbreakable, but it does put into perspective the perception of fragility that accompanied its early introduction to alpine skiing.
