Study proves Fat skis are bad for your knees

I’ve posted several times that narrower skis allow you to ski better and my personal observation is that my knees feel much better on a narrower ski than a fat one.  Scientific studies now prove this to be the case.  Also examines differences between groomers and powder, muscle usage and fatigue and towards end tele
Spoiler alert at Psia Level 3 ski width accounted for over 2/3rds of exam success

It’s long but worth it to watch if your knees bother you at all

Sorry I couldn’t get it to embed maybe Harv can fix it

https://youtu.be/ynVcTIHPkUo

Video embedded.

Z wrote

Spoiler alert at Psia Level 3 ski width accounted for over 2/3rds of exam success

Not sure what you are saying here?

As Al Kiner used to say, here's the happy recap:

Don’t know if they’re good for my knees or not but I for one love my old skinny skis and this dude agrees with me

I agree that slide seems confusing without the context of the whole presentation
If you watch the whole thing that slide was used as a starting point of discussion at Psia’s National Academy on how width can be used as a tool.  

The discussion from there was that there are some potential uses for lower end skiers given that the ski is a wider more stable platform but by day 3 the new skier would be on something 70 to 75mm wide.  Sort of a GLM method but with width instead of length.

95% of the presentation covers the negative impact to knees and the adaptation to their skiing that even world class skiers make to their technique to lessen the impact on the knee that then leads to soft issue issues with gluts hamstrings etc etc

I’ve personally lived thru all this experiment the last couple years.  My PT kept saying I can’t understand why your soft tissue gets this f’ed up from skiing.  I went to 74mm underfoot ski and it all went away only to come back in the spring when I brought my 98mm skis back out.  

I'm pretty convinced it's old age that's killing my knees.

I imagine the type of snow is a factor in fat skis damaging impact?

My knees have been getting pretty messed up the last few years. It’s to the point that I’m ok with taking some time off from skiing.

Powder certainly negates the effect on the knee but the study found that the wide skis even in soft snow have an impact on how you ski and that has implications for soft tissue.  It used a min of 11” of pow the study otherwise you hit bottom

I’m not  dumping my fat skis on pow days or in spring corn but I am going to ski on a 74mm width the vast majority of my ski days as a result of this study

Selling my 84mm width as anything over 80 has a negative impact and I found my deacon 74s well out skied my rtm 84

I can't speak to the differences between wide and narrow skis and knee pain.

However in the past year, I've ramped up the amount of prehab that I do in the gym.  Clamshells, single leg bridges, lateral walking with a mini band, and other stuff.  RESULT:  I have less knee pain than I did a year ago.

Still lifting heavy with dead lifts etc but the prehab really seems to have made a difference.  I'm even thinking that it's possible to run a marathon again.

Z wrote

I’ve posted several times that narrower skis allow you to ski better and my personal observation is that my knees feel much better on a narrower ski than a fat one.  Scientific studies now prove this to be the case.  Also examines differences between groomers and powder, muscle usage and fatigue and towards end tele
Spoiler alert at Psia Level 3 ski width accounted for over 2/3rds of exam success

It’s long but worth it to watch if your knees bother you at all

Sorry I couldn’t get it to embed maybe Harv can fix it

https://youtu.be/ynVcTIHPkUo

For those who don't mind reading scientific jargon, here's the paper associated with the presentation.

http://www.montana.edu/ehhd/ord/Seifert%20Ski%20Width%20seminar%20draft%20manuscript.pdf
Does Ski Width Influence Muscle Action in an Elite Skier? A Case Study
John G. Seifert 1, Heidi Nunnikhoven 1, Cory Snyder 1, Ronald Kipp 2
1 Montana State University Movement Science Laboratory Bozeman, MT 59717
2 Olympic Valley, CA

The skier they studied was Debbie Armstrong and the runs were taken at Steamboat.

Harvey wrote

Z wrote

Spoiler alert at Psia Level 3 ski width accounted for over 2/3rds of exam success

Not sure what you are saying here?

I think he's saying that, of people going for level 2/3 PSIA exams, 2/3 of the successes were on "skinnier" skis? I think?

The thing about beginners benefitting more from fat skis is kind of an oddity. The slide is a bit weird out of context, but it notes the differences in technique.

A few years ago, Ski Magazine had a bright idea to have "normal" people test skis (alongside the ski instructors, patrollers, & industry pros that usually test skis). They couldn't figure out why the beginner/intermediates liked the fatter skis so much, especially because a lot of them were stiff, unforgiving, and had less sidecut than the skis that were targeted to people at their ability level. But it turned out that the skiers liked those skis because the technique they were using didn't really jive with the skis that Ski Magazine thought they'd like.

A lot of lower level skiers use a "throw em sideways" method of turning that is wholly inconsistent with the way that skis are designed to be used. Advanced/expert skiers use more gradual tipping of skis to get the ski on edge, then let the sidecut do the work for them (which is more efficient & lets more advanced skiers ski longer while using less muscle energy).

What Ski Magazine found was that the fat, stiff skis were preferred for skidding. The fatness increased lateral stability, and the stiffness ensured that there wouldn't be weird flexes when these beginners applied 100% of their edging movements at the end of every turn.

The knee issues for fatter skis seem mostly associated with skiers who use their edges as deigned. If you rip around with your knees touching each other, tailgunning and buttering all over the mountain, the study is not for you.

Peter Minde wrote

I can't speak to the differences between wide and narrow skis and knee pain.

However in the past year, I've ramped up the amount of prehab that I do in the gym.  Clamshells, single leg bridges, lateral walking with a mini band, and other stuff.  RESULT:  I have less knee pain than I did a year ago.

Still lifting heavy with dead lifts etc but the prehab really seems to have made a difference.  I'm even thinking that it's possible to run a marathon again.

Those are all exercises I did as part of knee rehab after blowing an ACL (not skiing).  I opted out of ACLr surgery.  What I do instead is do the exercises year round that help strengthen hamstrings because they are doing more of the work of supporting the knee without an ACL.  Doesn't require that much time and can be done at home.  Combined with lessons to improve technique, I'm skiing more challenging terrain with less effort than 10 years ago before the knee injury.

I never had knee pain while skiing, before or after the knee injury.  But my ski buddy (pushing 70) with a wonky knee (no meniscus since high school) did have days his knee bothered him.  I've noticed he rarely bothers to use his powder skis (100mm).  Some trips he doesn't even stick them in the ski box (always drives).  He was using RTM84 for a while, then shifted to NRGY 90.  He's looking for new skis but more likely to go with mid-80s than mid-90s.  He was an advanced skier in high school skiing bumps at Aspen.  But lessons with very experienced instructors (20+ years at Level 3) in recent years have smoothed out his skiing a lot.  He's skiing longer days and harder terrain at places like Alta and Taos.

The title of this thread is misleading....  As my father used to say, any job is easy if you have the right tools.
Same goes for skiing.  Different skis for different snow conditions.