Ski Width and Biomechanics

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Ski Width and Biomechanics

Postby gozoogle » Mon Jan 10, 2022 11:40 am

I was having a debate over the weekend with a wide ski lover, and I ended up looking to see if research has been done in this area. Found these two things interesting so I thought I'd share:

Research published in the Journal of Sports Science & Medicine (2015) by Martin Zorko (Ljubljana University Medical Centre) et al:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541126/

Article on professor John Seifert's (Montana State) overview into current research into wide skis: https://realskiers.com/revelations/why- ... our-knees/

The TL;DR summary from the article:
- Physics doesn’t lie. All the supporting numbers from various research projects may not be a complete match, but they come very close.
- Knee injuries are positional in nature. The tall stance induced by wide skis takes the muscles supporting the knee out of their ideal length-tension angle.
- The strain required to overcome Ground Reaction Force (GRF) on hard snow causes skiers instinctively to drift instead of edge, thereby losing a measure of control.
- To mitigate the risk associated with their use, wide skis need to be in powder around a foot deep. Even if you find fresh snow this deep, how long does it last? Once powder turns into crud, GRF raises its intensity.

- The best protection against injury is good ski technique. [PMTS has entered the chat!]
- If you don’t already possess strong technical skills, a wider ski will hinder your skills development. [Yes, you should get that sub 70mm SuperShape to learn on...]

This is all affirmation of what I see being discussed here. So really my only question is how do I get a job as a professor specializing in Skiing as a research area?!
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Re: Ski Width and Biomechanics

Postby GregM » Mon Jan 10, 2022 8:15 pm

No argument about narrow skis being better for learning.
I just wanted to point out -- the quick look at this old publication by Zorko. Look at the Fig.1 -- how the "expert" skier is horribly A-framed and weight is on the inside ski in both narrow and wide ski examples. Might be misaligned or the luck of technique or probably both.
I recall Harald's joke about the PMTS presentation at International Congress on Science and Skiing, with him saying that all those scientists can argue about skiing, but when they went in a group to ski -- those guys just cannot ski :).
I think this is one of those examples of the scientist who cannot ski analyzing a highly skilled skiers who are actually hacks. Wide skis require a much better technique and are not a free pass to any terrain as they are saying trying to sell those, but I think with the proper technique, wider skis might be used quite well and I see all experts on this Forum having and using those.
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Re: Ski Width and Biomechanics

Postby gozoogle » Tue Jan 11, 2022 6:05 pm

Agreed, I think that’s the point. Many/most skiers have bad technique and wide skis will just make it more difficult. Catch-22… you can overcome the width with good technique, but you’ll struggle to develop that while on wide skis. And this is only up to a point, I’m assuming even the expert PMTS skiers would not have a good time with ski widths approaching 120mm.

I really don’t understand why the North American market has become dominated by wide skis. Most ski shops and rental shops simply don’t carry sub 70mm skis… you generally see only a model or two at high end rentals or shops selling to racers.
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Re: Ski Width and Biomechanics

Postby BrettBPotter » Wed Jan 12, 2022 5:15 pm

Marketing and 4 color magazine photos are a powerful influence. Ironically no other sport markets products that the best athletes in that sport don't even use. In Mammoth other than the racers and Master skiers, you don't see 10 sub 70mm waisted skis in a day.
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Re: Ski Width and Biomechanics

Postby h.harb » Thu Jan 20, 2022 11:26 am

I just skied with one of my friends who skied his whole life. I had never skied with him before. He used to work at Mt Snow way back, he's also an attorney but a self-taught skier. Everything he has ever heard about skiing is PSIA derived; feet apart, stand on both skis and extend. In one morning, I was able to show him the opposite. I canted his 2 sizes too big boots and I swapped skis with him. He was on a 95mm underfoot piece of shit. I skied his skis and hated them. They were hard on the knees, I could carve them but had to open up the turns and ski at about 45mph.

My friend had the typical, down the falline, high-speed tail pushing turns, actually, they were not turns at all, just lined skids. We worked on releasing the outside ski, lift with tipping, stay bent/flexed, and I had him holding his poles correctly by keeping his pole tips on the snow. He was athletic enough to get the idea on my Head eOriginals. He got it, he felt the carve experience.

He is now so excited about skiing on groomers. He hated skiing groomers before this. He is so excited about new skis and has already bought new boots. Part of what most skiers on wide skis are experiencing is the lack of results or changing ability, due to terrible products and poor alignment. Wide skis require you to ski with a horrible adaptive technique.

The ski industry and the manufacturers have ruined skiing for many. Skiers don't have anywhere to go to get good information. I watch Youtube videos by many of the so-called experts, even Richi Berger and Reilly, there is so much wrong or mileading information about skiing out there.
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Re: Ski Width and Biomechanics

Postby h.harb » Thu Jan 20, 2022 11:38 am

Let me explain why I say that even experts like Ricki and Reilly don't get it. First of all, they teach the same methods from their national systems, not how they ski. I can't figure out why they don't teach how they ski, it is amazing.

Also, they don't teach many low-level skiers they haven't figured out where people go wrong and how their progress stops. I have spoken with a few advanced skiers who have attended both our camps and the Rookie Camps with some of the Demo Team skiers who teach those camps. The common response is, they don't teach the "HOW" of movements, they try to give "student outcomes" and add a few tips. In other words, they don't teach movements that create the results you want. I know watching our students, you can't build long-term results using outcomes.
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Re: Ski Width and Biomechanics

Postby Basil j » Wed Feb 23, 2022 7:20 am

I am an east coaster skier and unfortunately my world is mostly hard pack groomers with the occasional powder day that quickly turns to chop. I ski up at Cannon and Waterville valley most of the time with occasional trips to Killington, Burke, loon ETC. What I see all over the east is that technically proficient skiers can handle wider skis and I am often surprised at some of the carving I see skiers doing on wide boards, but you can tell these skiers are either former racers or have had good training and know what they are doing. That''s a small percentage. the rest of the people I observe are skidding, throwing their tails out and basically adapting to the ski they have on their feet instead of using it as designed. When I go into ski shops the narrowest skis I usually can fine are 80mm under foot. Anything narrower is marketed as a learning ski and they are low level products. Its such a disservice to their customer base because people buy skis for the conditions they hope to ski in, not what they actually end up skiing. One of my best friends has been on Bonafides for the last 4 seasons and i always try to get him on a narrow ski without much luck. This season with low snow pack I got him to try my Dynastar speed zone Ti's and the difference in his skiing was dramatic. So much so, that he bought them off me the same day and they have now become his primary ski. he has gone forma one trick pony, to mixing up turn shapes during runs and has gone back to really utilizing the outside ski, where as before on the Bonafides he was much more 2 footed. When I read the ski mags and they market 84mm and 88mm skis as carving skis, I cringe because the stress that these wider skis can put on your knees is great, and they can't carve like a sub 72mm ski. It's all Marketing, albeit bad marketing. I ski my Speedzone 14's 90 % of the time and they get me through everything , except deep powder with ease. My deep snow ski is a legend 84 and I don't need anything wider.
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