Study of 392 ACL injured out of 1817 skiers suggests which parameters could be considered to reduce the likelihood of ACL injury in rec skiers

[AlexisLD]

Yeah but it wasn't my conclusion. It was the authors' conclusion. I literally just copy pasted their conclusion.

Are you saying you disagree with their conclusion? Or that their conclusion is wrong? Or that the conclusion is incongruent with their findings?

Dude, there are 4 paragraphs in that abstract. Read them all!! Not just the conclusion!

It is easy to imagine that they are trying to put something flashy in their conclusion so people talk about it. Everyone knows that low-skill is linked to falling (and a bunch of other more important factors). They can't talk about that because it is not a new conclusion. They have to talk about something else to be published in a research journal.

Again, I haven't read the paper because it is not accessible. It is important to read the full paper for these kinds of studies because they make so many assumptions for their results to be valid. What seems clear from their previous papers on falling is that they are commenting on one of the least important factors. Yes, they might have shown that some factors related to equipment are significant, but these factors might still remain amongst the least important factors to think about if you want to prevent an injury...

 

[Rich_Ease_3051]

Dude, there are 4 paragraphs in that abstract. Read them all!! Not just the conclusion!

It is easy to imagine that they are trying to put something flashy in their conclusion so people talk about it. Everyone knows that low-skill is linked to falling (and a bunch of other more important factors). They can't talk about that because it is not a new conclusion. They have to talk about something else to be published in a research journal.

Again, I haven't read the paper because it is not accessible. It is important to read the full paper for these kinds of studies because they make so many assumptions for their results to be valid. What seems clear from their previous papers on falling is that they are commenting on one of the least important factors. Yes, they might have shown that some factors related to equipment are significant, but these factors might still remain amongst the least important factors to think about if you want to prevent an injury...

... authors man. They could have just added another sentence "Higher age, lower skill level and riskier behaviours are also factors to ACL injury and needs more study". Or "Higher age, lower skill level and riskier behaviours are also factors to ACL injury and this study confirms previous findings".

But they didn't. I don't want to put words in their mouth. If they left that out, I would say it's not part of their conclusion. It's just one sentence they could have added, but didn't.

Assuming what they're thinking is disrespecting their expertise and the work they put in the study. And also their integrity.

 

[geepers]

Do not ski cautiously.

Could we re-phrase this to "Do not ski hesitantly"? Or better still move away from the negative to "Ski with commitment" (or some such).

Can see no issue with skiing cautiously (as in safely/prudently/alertly/heedfully/vigilantly) - just as long as it is not fearfully/tentatively.

 

[Andy Mink]

Could we re-phrase this to "Do not ski hesitantly"? Or better still move away from the negative to "Ski with commitment" (or some such).

Can see no issue with skiing cautiously (as in safely/prudently/alertly/heedfully/vigilantly) - just as long as it is not fearfully/tentatively.

My one glorious fall last season was due in part to second guessing my line. Ironically, I had skied the same line the run before just fine. I hesitated, stopped to think (well, not stopped stopped), and that was it. Luckily no injury.

 

[geepers]

My one glorious fall last season was due in part to second guessing my line. Ironically, I had skied the same line the run before just fine. I hesitated, stopped to think (well, not stopped stopped), and that was it. Luckily no injury.

Spend more than my fair share of time as the grape...

 

[François Pugh]

This just in!
Higher speeds cause more severe injuries! Who knew?
A ski designed with the goal of making easier to deliver forces to the skier results in greater forces being delivered to the skier and more skier injuries? Who knew?
I'll tell you who knew: (any) every engineer ever.

 

[AlexisLD]

... authors man. They could have just added another sentence "Higher age, lower skill level and riskier behaviours are also factors to ACL injury and needs more study". Or "Higher age, lower skill level and riskier behaviours are also factors to ACL injury and this study confirms previous findings".

But they didn't. I don't want to put words in their mouth. If they left that out, I would say it's not part of their conclusion. It's just one sentence they could have added, but didn't.

Assuming what they're thinking is disrespecting their expertise and the work they put in the study. And also their integrity.

Almost no research would be funded to demonstrate the obvious or something that has already been demonstrated. This is somewhat of a problem in science because it limits the number of repeat studies (https://undark.org/2017/09/11/replication-crisis-funding/). This is particularly a problem in fields like this where you analyze data using advanced stats. You have to do something new to receive funding and be published.

They actually state their objective pretty clearly (1st paragraph):
Objectives To evaluate the impact of ski geometry data and standing height ratio on anterior cruciate ligament (ACL) injury risk of male and female recreational skiers.

A good conclusion should go back and discuss your original objective. That is what they are doing. An abstract is limited in the number of words you can use. However, they still say in their results that "higher age, a lower skill level and riskier behaviour as independent individual risk factors associated with an ACL injury". They do not refute that fact by not talking about it in the conclusion of their abstract. They just want to use the conclusion to summarize their work in the context of what is new and their original objective.

This is not a paper about trying to reduce ACL injuries or identifying the most important factors. It is a paper about evaluating the nth factor that could have an impact on ACL injuries, with "n" being high. The only way to know how important ski geometry is compared to other factors is to buy the paper. But you can also look at their previous work to get a pretty good idea and identify n-1 better ways of reducing your chance of falling / ACL injuries.

I think we just want you to learn about the Pareto principle to protect your knees (https://en.wikipedia.org/wiki/Pareto_principle)!

 

[Philpug]

This just in!
Higher speeds cause more severe injuries! Who knew?
A ski designed with the goal of making easier to deliver forces to the skier results in greater forces being delivered to the skier and more skier injuries? Who knew?
I'll tell you who knew: (any) every engineer ever.

It is the slow twisting falls in the lift line or gradual terrain that is also a risk. When the binding expects 58Nm to release and there is only 19Nm the ligament is the weakest link.

 

[Rich_Ease_3051]

Almost no research would be funded to demonstrate the obvious or something that has already been demonstrated. This is somewhat of a problem in science because it limits the number of repeat studies (https://undark.org/2017/09/11/replication-crisis-funding/). This is particularly a problem in fields like this where you analyze data using advanced stats. You have to do something new to receive funding and be published.

They actually state their objective pretty clearly (1st paragraph):
Objectives To evaluate the impact of ski geometry data and standing height ratio on anterior cruciate ligament (ACL) injury risk of male and female recreational skiers.

A good conclusion should go back and discuss your original objective. That is what they are doing. An abstract is limited in the number of words you can use. However, they still say in their results that "higher age, a lower skill level and riskier behaviour as independent individual risk factors associated with an ACL injury". They do not refute that fact by not talking about it in the conclusion of their abstract. They just want to use the conclusion to summarize their work in the context of what is new and their original objective.

This is not a paper about trying to reduce ACL injuries or identifying the most important factors. It is a paper about evaluating the nth factor that could have an impact on ACL injuries, with "n" being high. The only way to know how important ski geometry is compared to other factors is to buy the paper. But you can also look at their previous work to get a pretty good idea and identify n-1 better ways of reducing your chance of falling / ACL injuries.

I think we just want you to learn about the Pareto principle to protect your knees (https://en.wikipedia.org/wiki/Pareto_principle)!

Good point. Yeah I think I read something about that, that confirmatory studies isn't gonna get you grant funding or whatever. Grant funders only want to give money to new studies.

And something about grant funders only giving money to those academics that would prove the grant funders' biases.

And that some ridiculous amount of studies, like 90% or something, cannot be replicated anyway.

Good points all around I retract my previous statement.

 

[dbostedo]

...were associated with a reduced likelihood for ACL injury.

For anyone who's actually read the paper, does it say how correlated they were and how much the likelihood was reduced? (And what the error bars are on that data?)

 

[Rich_Ease_3051]

This is not new information This was addressed more than a decade ago by Volkl with women's skis and thier Biologic ski/binding combined that had more taper in the tail and the binding moved back and with a negative delta. All because women are more susceptible to knee injuries than men.

Does Volkl still use this Biologic tech with the recent females skis? They're going away from shrink it and pink it right? And there's a drive from reviewers like the Blister guy "to unisex" ski products, particularly skis?

 

[Philpug]

Does Volkl still use this tech with the new females skis? They're going away from shrink it and pink it right? And there's a drive from reviewers like the Blister guy to unisex skis?

Volkl never really subscribed to "Shrink it and Pink it", either they used a unsex ski and put a feminine graphic on it ir made a truly women's specific ski.

 

[Rich_Ease_3051]

Volkl never really subscribed to "Shrink it and Pink it", either they used a unsex ski and put a feminine graphic on it ir made a truly women's specific ski.

So the Biologic tech was a one off?

 

[Philpug]

So the Biologic tech was a one off?

Yes,

But if you look at a lot of current Volkl/K2 and Blizzard/Nordica system skis, they have a negative delta. But it is also the taper in the tail that helps the tail release in rear ward twisting falls that helps mitigate knee injuries.

It will be interesting how the Tyrolia Protector helps, there is some design aspects like a higher stack height and 5mm of delta that can make some release angles tougher. This IMHO is doe to inherent design, they need roon under the heel for the mechanisms and they beleive that a positive delta cannot be lost for performance.

 

[Rich_Ease_3051]

If you read the comment section of the original article I linked,

Changing Ski Type Reduces ACL Risk | Orthopedics This Week

Changing Ski Type Reduces ACL Risk

ryortho.com

there's a lone comment from Rick Howell (or someone who purports to be him).

So what's the deal with the Rick Howell guy? I've seen his name floating around in this forum a lot. Not as a commenter, but people saying "Rick Howell thinks or did so and so".

Seems to me like the Tyrolia Protector is similar to his binding? Wonder what his thought is about that?

 

[James]

…and smoking are associated with falls in a cohort of 1607 recreational skiers and 373 recreational snowboarders.

Next data analysis- increase in injury in States that have legalized pot.

 

[Philpug]

If you read the comment section of the original article I linked,

Changing Ski Type Reduces ACL Risk | Orthopedics This Week

Changing Ski Type Reduces ACL Risk

ryortho.com

there's a lone comment from Rick Howell (or someone who purports to be him).

View attachment 174988

So what's the deal with the Rick Howell guy? I've seen his name floating around in this forum a lot. Not as a commenter, but people saying "Rick Howell thinks or did so and so".

Mr. Howell was at the forefront of knee protection going back to the 1970's with his days at GEZE. He designed the Kneebinding and now has his Howell Binding designed to come out in the near future.

Seems to me like the Tyrolia Protector is similar to his binding? Wonder what his thought is about that?

While there are some similarities, I am sure Tyrolia did their due diligence not to have any patent infringements. As far as his thoughts on the binding, we cannot begin to speculate.

 

[Philpug]

If you try to stop a fall then you are falling.

You shouldn't reach that point. When you are falling let yourself fall. But don't start falling is even better.

Some will say that skiing as a whole is a series of linked recoveries.

 

[KingGrump]

Some will say that skiing as a whole is a series of linked recoveries.

Hey, I resemble that statement.

 

[Rich_Ease_3051]

For anyone who's actually read the paper, does it say how correlated they were and how much the likelihood was reduced? (And what the error bars are on that data?)

Just want to add: to someone who has access to the paper, what is their definition of wide and narrow tip?

Think I will make my next ski have their recommended parameters. Plus the Tyrolia Protector.