Boots or Straps?

Choice of hardware in sports is of great importance. Especially when this hardware is in immediate contact with the athlete and is directly related to sports safety.¹

About KiteMedical blogger: Leon Meijer
Leon Meijer is a sports physical therapist with fysiosportief in Groningen (Netherlands) and a fanatical kite surfer himself. He and Roeland den Boer (sports surgeon) together led Youri Zoon's recovery after surgery on his shoulder.

Your equipment

In the kite surfing world, both the hardware and environmental factors have a proven influence on the safety of the sport. (2,3,4,5) The hardware must be designed well ergonomically in order to provide maximum performance and to reduce risk of injury at the same time. (1,4,6)
Connecting the kite surfer's feet to the board is done either with straps or boots. Straps are most commonly used among kite surfers (92%). A 2012 research conducted by Lundgren shows that 12% of the questioned kite surfers uses boots occasionally to get a better feel for the board.¹
Boot users mentioned during the research that their techniques and tricks are different from the times they use straps. Furthermore, the researchers found that straps don't see much use with wave surfers.

Nowadays (2015), boots are an increasingly common sight among kite surfers. The kitesurfing greats like Youri Zoon & Steven Akkersdijk all have their own specific reasons for choosing boots over straps. Using boots allows you to transfer power from the knees, water and board much more efficiently.
Using straps, you're not really attached to the board. With boots however, you're secured to the board firmly. Boots not only allow for a better transferring of power but also provide control and stability. Another advantage is your feet unable to slide out like they do with straps.

In short, with boots you can initiate Freestyle tricks harder using more power with more control.
It is suggested that the damping properties of boots is better for the knees and other joints but this really comes down to the materials in each particular boot. Some straps have great damping properties and surely many boots do a bad job at damping shocks or even not at all.
Just like running shoes, there is great variety in actual comfort and shock absorption.

Are we, recreational kitesurfers actually waiting for a development like boots?

What are the downsides of using boots instead of straps? Especially considering the limits of the human body? What happens to our joints when we crash wearing boots? Which body parts run the greatest risk of injury? All questions without straightforward answers. Everything is directly and indirectly related to:

• age,
• body weight,
• build,
• choice of hardware
• kitesurfing experience.

What we can be sure of - whatever above mentioned factors might be: crashes while wearing boots will hit harder than crashing in straps. With boots, the board is firmly fixed to the body. This usually makes things come to an immediate and full stop in the water, causing all sorts of problems during the crash. Add to that the kite getting steered through the powerzone whether willingly or by accident, nasty forces will start working on the body (knees, back and shoulders especially)
In case the foot stays fixed inside boot, there is an increased chance of multi-ligament injuries of, for example, the knee.

When the kite or crash doesn't pull you out of your boots, or your board doesn't break, all forces are released on the body directly.
It is therefore of great importance that research be conducted on the amount of force necessary to leave in place - for example, the inserts. For this, a measured average breaking point should be found. Not giving thought to such factors could result in kitesurfers either kicking loose the inserts too easily or the inserts not coming off at all. It needs no explanation both cases might result in injury.

Hardware decisions should be made depending on the kitesurfing style.

High jumps with a kiteloop? In this case straps would be the better choice since the body gets to endure a lot during such crashes.
Is the style focusing more on handle passes, unhooked actions or raileys, more board control is demanded?  In this case going for boots would be a more logical choice.
All this is again influenced by before mentioned factors such as age, bodyweight, etc.

Youri Zoon

Looking at Youri Zoon, new factors come into play while looking at the hardware used. Youri is truly a professional whose physical limits are incredible. Add to this his amazing talent for kite surfing and it's easy to see he's able to relay a great amount of power through physical ability and technique. In Youri's case, inserts would need to be strengthened so he can apply maximum force without the inserts giving away. One of the inserts failing under such amount of stress would release a great amount of force on ankle, knee and hips, possibly resulting in serious injury (usually multiple).

It goes without saying that the average kite surfer wouldn't need inserts as strong as mentioned above. What’s worth mentioning however is with boots much larger forces work on the inserts than with straps. A boot has a steel base plate, which attaches on two points. Because your foot / ankle is locked into the boot it forms a lever which can produce large forces. This isn't the case with straps. As soon as you lift your heel, there is no more lever and as such the forces don't build up as much as with boots.

Taking into account all of the above, it is very important for designers of kiteboards, straps and boots to keep in mind for which type of kitesurfer the hardware is being designed. Extra strong inserts for the likes of Youri Zoon, and a grade below, but still greatly sufficient, would exist hardware designed for the average kitesurfer.

Having said all that however, it would be impossible to develop a unique type of board, strap or boot for each individual. Every athlete has their own set of demands and preferences when it comes to kite surfing hardware and every athlete has his or her own physical limits. To minimize risk of injury it is very important to make educated decisions on the type of hardware that fits you. Sadly, little scientific research has been conducted so far to map out the amount of forces playing on the body during kite surfing.

Boots or straps? What do I have to ask myself?

Now ask yourself this: are you performing tricks unhooked? If the answer is no, then straps will serve you just fine.
We asked Steven Akkersdijk for his opinion on beginner kite surfers wanting to switch to boots as soon as possible. “Are you used to surfing unhooked yet? Which advantage do you expect to find in using boots? Make an educated decision with these questions and the information in the above article in mind.” And Youri Zoon on using boots: “Just enjoy kite surfing without injuries!”

For medical questions related to kite surfing, find Leon Meijer and Roeland den Boer on twitter: @leonmeijer2009 and @roelanddenboer.

References

1. Lundgren L, Brorsson S, Osvalder A-L, Injuries related to kitesurfing. World Academy of Engineering and Technology 77 (2011).
2. Nickel C, Zernial O, Musahl V, Hansen U, Zantop T, Petersen W, A Prospective Study of Kitesurfing Injuries. The American Journal of Sports Medicine 32 (2004), 921-927.
3. Petersen W, Nickel, C., Zantop, T., Zernial, O., Verletzungen beim Kitesurfen. Der Orthopäde 34 (2005), 419-425.
4. Spanjersberg WR, Schipper IB, Kitesurfing: when fun turns to trauma-the dangers of a new extreme sport. The Journal of Trauma 63 (2007), 76-80.
5. Reilly T, Lees A, Exercise and sports equipment: Some ergonomics aspects. Applied ergonomics 15 (1984), 259-279.

Category: Kites