Snow and ice can make driving treacherous, of course, but snowfall -- especially the wet, heavy kind -- can be dangerous even if you never leave your driveway. Each year, shoveling piles of snow after a storm is believed to cause tens of thousands of back and shoulder injuries in the United States, not to mention several hundred heart attacks.
Overall, more than 70,000 people ended up with a shoveling-related injury bad enough to trigger a doctor's visit in 2008, according to the Consumer Products Safety Commission. A quarter of those people visited an emergency room, and about 900 were admitted to a hospital.
The exertion, cold weather and slippery surfaces snow shovelers face are a dangerous combination, especially if it's an activity you're not used to. Snow shoveling "is one of the most high-intensity exercises you can do," says Suzanne Steinbaum, D.O., a preventive cardiologist at Lenox Hill Hospital, in New York City. "You're using all your major muscle groups."
But there are steps you can take to shovel safely and ensure that you survive the winter in one piece.
The number-one injury sustained after a snowstorm is lower back strain, according to Henry Goitz, M.D., an orthopedic surgeon at Henry Ford Hospital, in Detroit, and a spokesman for the American Academy of Orthopaedic Surgeons (AAOS). "That's when a muscle gets over-tensioned and tightens," he explains. "If it over-tightens, it's almost like a spasm and that gets very painful."
Another common back injury incurred during shoveling is a herniated disk, says Victor Khabie, M.D., the co-chief of orthopedic surgery at Northern Westchester Hospital, in Mt. Kisco, N.Y. A herniated disk (also known as a slipped disk) is when one of the soft disks between the vertebrae comes out of position and pushes on a nerve.
If your post-shoveling recovery includes back pain that radiates down your leg, it's a bad sign. "That may mean you have ruptured or herniated a disk," Dr. Khabie says.
The combination of frigid weather and normally sedentary people going all-out can be a recipe for back injuries. "The shoveling tends to be done by people who are not otherwise in good shape," says Richard Pomerantz, M.D., a professor of medicine in cardiology at the University of Rochester Medical Center, in Rochester, N.Y. "Sometimes a potato chip is the heaviest thing they've lifted for a while."
The snow is not the only danger. Ice lurking underneath snow can potentially cause even worse injuries. Evalina L. Burger, M.D., a vice chair and associate professor of orthopedics at the University of Colorado, in Denver, says she has seen no acute injuries from shoveling over the past three years but "horrible injuries from slipping on ice, including bad fractures."
"The worst thing is a fall," she says. "It's not just old people who fall."
Though rare, heart attacks that occur while shoveling snow have a long-standing place in medical lore -- much like heart attacks that occur during sex.
In the late 1970s, researchers from the Centers for Disease Control and Prevention studied six major snowstorms in Massachusetts (including the record-setting Blizzard of '78), and found that heart disease-related deaths rose by 22 percent in the week following a storm. Men were responsible for the majority of the spike, which "might be explained by snow shoveling," the researchers noted.
The combination of exertion and cold weather are believed to be the cause of shoveling-related heart attacks. "We don't like heart patients doing tons of heavy weight lifting coupled with cold weather," says Dr. Pomerantz, whose home of Rochester averages about 7 feet 8 inches of snow each year.
There's both an aerobic and weight lifting component to snow shoveling, says Dr. Pomerantz, and the weight lifting portion can raise blood pressure. "You're increasing the load on the heart very, very quickly when maybe the heart is not used to it," he says. "If you do that in a setting where it's cold, your arteries and vessels tend to constrict, so the relative blood supply goes down at a time when you're asking the heart to do a lot more. Demand is high and supply is low and that can be too much sometimes."
Moreover, hormones released during cold weather and exercise can cause plaques -- fatty deposits that line artery walls -- to rupture, leading to blood clots and heart attacks. "If you have plaque in your arteries, this is a perfect time for them to rupture and lead to a heart attack," Dr. Steinbaum says.
Timing may also be a factor. According to a 1996 study in the American Journal of Cardiology, many people shovel in the early morning, when the risk for heart attacks is higher.
- Stay in shape. People who are in shape year-round have less to worry about when the flakes start falling.
The cardinal rule is to practice a bit of common sense. As with any exercise, if you're out of shape, have had back injuries in the past, or have a history of heart disease, check with your doctor before tackling that snowdrift. This is wise even if you don't have heart problems but have high blood pressure or diabetes, or are overweight -- all of which are risk factors for heart disease.
For some people, the safest thing to do might be to outsource the job to a son, daughter or neighborhood teenager who's looking to earn a little pocket money.