Physics Class

Justin over at ski-blog.com came across an interesting little article on statistics for snowsport injuries. The interesting bit to me was this line:

Helmets are designed to protect your head up to 12 mph, however, most collisions with trees involve the skier/boarder traveling at least twice to three times that speed.

For some reason the 12 mph really stuck out in my head. First I'd like to know where that number originated from, as I've been unable to find any stats to back the number (and the cited data source doesn't seem to mention it) . But let's assume it's true for the sake of this post and correct me where I may have gone wrong in calculations and/or reasoning. Following the Coast Guard CHRIS Manual's conversion factors 12 MPH * 0.4470 = 5.364 meters per second. Assuming no other factors and our head drops straight down from a 1.80 m height (look 180 cm skis), we'll be moving at a speed of 5.939 m/s. [Here's the math: 1/2 * m * v^2 == m * g * h ==> sqrt(2 * g * h) = v. G = 9.8 m/s/s and h = 1.80 m]

That number seems to exceed the maximum impact absorption rate of the helmet. The International Society for Skiing Safety lists a Snell standard for a flat anvil hit on a helmet as 14.1 mph which puts the impact rating at 6.3027 m/s and safely in a flat fall impact range (unless you stand over 2 meters in height).

I'm not sure where this post is going, but I'm putting it online even in it's unfinished state. Hopefully some readers will have feedback on how far off I am.

NYTimes Pumps Skiing

The New York Times has an article (no promises the link will work) titled " Out of Deep Freeze: Freeskiers Make Sport Cool Again" written by Matt Higgins. Not a terribly well written piece, it seems most of the opinions come from a discussion with Tanner Hall and Peter Olenick. An interesting data point though, one which I've talked about here as the swinging of skier vs snowboarder classes heading out (and if today is any indicator it's not changed this year either).

In 2004, there were 6.5 million snowboarders and 5.9 million skiers. But the next year, the trend reversed course. And in 2006 — the most recent year for which figures are available — there were nearly 6.4 million skiers and 5.2 million snowboarders.

He's actually found data to substantiate the trends we've seen on the mountain. Awesome! Although I never thought it surpassed snowboarding... wow.

Although overall sales for Alpine skis have been down in recent years, sales of twin-tip skis are soaring. From August to November 2007, twin-tip ski sales were up 50 percent over the same period last year, said Alicia Allen, a spokeswoman for the trade group SnowSports Industries America.

Now this is the one that surprises me a little. Yeah most of the folks I meet these days are riding twin tips, but these are the same people I never see riding the park or doing tricks. I'd argue that twin tips are really what the industry is pushing for equipment design. Most fat skis these days have twin tips. As much as I hate to admit it as a factor for a decision on a ski, a lot of the more edgy/progressive ski top/bottom-designs are on twin tips, and style sells (face it Völkl Tigersharks look just blech but they're a ripping ski). Both are issues outside the realm of articles topic of discussion, but Matt if you're reading they're a good follow up.

Back to Work

I'm back on the mountain again, finally! While I'm not teaching classes right now I am helping the sales, hosting guests, and in general loving being back on the mountain these days. My time outdoors is limited by the lack of gloves that fit a cast, but I'll take what I can get in doses. Now I've got to learn to eat an earlier lunch...

New Cast!

Thanks to a short visit to the orthopedic clinic today, a few x-rays, and a good diagnosis I can now bend my right elbow. It's been almost four weeks since I've done this last and it feels... weird. I've been carrying my arm bent all day for no reason other than it feels right. Oh and the new cast smells a lot better...

Yikes

And just to prove an earlier point, helmets while a great thing are not the save all. Scott Macartney this weekend took a nasty spill at the Kitzbühel races. The impact appears to have knocked his helmet clear off his head (video footage can be found online elsewhere). I'm sure the damage would have been worse had he no helmet, but the impact looked pretty bad.

Good news is there are plenty of reports saying he has been making some great strides in recovery. Good luck Scott, and hopefully you and I will both be back on the skis in no time. :)

Car Park

In what must be the most interesting ad for a car that I can think of, Subaru apparently let one of their rally drivers loose on a snow terrain park somewhere. I certainly would love to have had a chance at riding shotgun on this taping. Waaay to much fun here :-) Enjoy..

Two Weeks

Two weeks since my accident, and this is what my arm continues to look like. I've contrast enhanced the image to show the break a bit better for those of you (like me) who are not in the habit of reading bones.


Yummy... a nice break slowly healing. Vision in my eye returned a few days after the accident. Apparently I needed to wait until the swelling went down to get that back. Seems to be normal, although the doctors are keeping a close watch on this.

The cast runs from finger tips to mid-bicep, making things like typing, putting on long sleeves, or jackets really difficult. Forget tieing shoes or wearing gloves. Until that changes I've been working very little.

The Season That Was Not

It's amazing how a single moment can change your life. On Dec 27th my season came to an end with a series of events so fast paced I'm still trying to piece them together. Since I've only got one hand to type currently, the short version for now. The longer version will come later.

After a full day of 4 and 5 year olds I assisted in a restocking run to the mid-mountain lodge. Up the chair with 10 lbs of sausage and 8 gallons of water. Returning at the bottom, I was involved in 3 person collision, where I got hit head on. My right arm is broken in multiple spots along the radius. My left was spared apparently thanks to the wrist brace I was wearing (although the metal brace was bent hard). Helmet was broken, and my left eye crushed.

Vision is slowly coming back to my eye, my face is finally starting to lose the swelling, and my arm itches like crazy. Typing is slow and difficult right now.

SkiPatrol's general opinion was the helmet saved me from any further damage. Best case I can be back out for some spring skiing, but the prognosis isn't likely. For now my season is over. And my bed calls for more sleep.