Sledding, Physics and Helmets…All Part of the Same Equations

sledding_largeDon’t tell this to my kids – but my favorite place to sled as a kid was a hill in the woods behind a friend’s house. And, my second favorite hill was at the high school, Senior Hill, which ended at the driveway entering the campus. Talk about violating just about every sledding rule there is! If I only knew then what I know now.

The statistics on injuries from sledding may surprise you. The Consumer Product Safety Commission estimated that 14,000 kids ages 5-15 were treated for sledding injuries in 1997. In 2003, the CPSC reported over 90,000 total ER visits for all sledding injuries with half occurring in people under 20 years of age. Luckily, most injuries are minor – cuts, sprains and strains, but fractures, dislocations, facial injuries and serious trauma to the head and spine do occur. And, the younger a child, the more they are at risk for the more serious types of injuries.
Even knowing these statistics, all too many people tempt fate and convince themselves that it’s possible to defy physics. What they fail to realize is that the physics of sledding actually explains why sledding is so dangerous and supports the adage ‘the bigger you are, the harder you fall’. Very young kids are the only exception. Young children are more vulnerable to injury because of how large their heads are compared to their bodies which raises their center of gravity compared to ours.

If you think back to your school days, you’ll likely recall Newton’s First Law of Physics: Force equals mass times acceleration or F=MA. The greater the weight on a sled and the steeper the grade, the greater the force generated that pushes you down the hill. If it weren’t for the safeguards nature builds in with competing forces we’d end up going infinitely fast. When sledding, the friction of the snow and the wind pushing against us do slow us down but we can still clock speeds of 20-25miles per hour.

Add to speed and slick snow sleds that don’t steer and obstacles often covered in snow and the result is out of control sleds and falling people. The other major downhill winter sports, skiing and snowboarding, have professional programs we can fall back on to master some skills and reduce injury. Sledding is also different in that experience doesn’t make us more competent. F=MA will win all the time.

So, what can we do? Sled smartly. The American Academy of Orthopedic Surgeons (AAOS) offers the following tips to make your next run as safe as possible:

* Parents or adults must supervise children, while sledding, at all times.
* Sled only in designated areas free of fixed objects such as trees, posts and fences.
* Do not sled on slopes that end in a street, drop off, parking lot, river or pond.
* All participants must sit in a forward-facing position, steering with their feet or a rope tied to the steering handles of the sled. No one should sled headfirst down a slope.
* To protect from injury, it is important to wear helmets, gloves and layers of clothing.
* Do not sit/slide on plastic sheets or other materials that can be pierced by objects on the ground.
* Use a sled with runners and a steering mechanism, which is safer than toboggans or snow disks.
* Sled in well-lighted areas when choosing evening activities.
* Individuals with pre-existing neurological problems may be at higher risk for injury.

Let me highlight a few additional tips especially relevant to kids:

* Never sled alone
* Make sure that the child is strong enough to control the sled
* Make sure the kids are old enough to understand the need to hold on
* Develop a safety plan that your kids can follow in case someone gets hurt
* If you enforce no other rule, enforce this: no helmet, no ride – and that should be true for adults and kids.

So, have fun the next time you test physics in motion…but when you sled, don’t forget to protect your head!