It happens every winter: Someone who hasn't lifted more than a pencil recently heads out to clear the driveway after a heavy snowfall. Results can range from sore muscles to back and shoulder injuries to a heart attack.

In 2006, more than 31,000 people in the U.S. were treated in hospital emergency rooms, doctor's offices, clinics and other medical settings for injuries caused by manually removing ice and snow, according to the National Electronic Injury Surveillance System, an arm of the U.S. Product Safety Commission that tracks product-related injuries treated in hospital emergency rooms nationwide.

Shoveling also increases the risk of a heart attack. Typical winter conditions (a little more than an inch of snowfall and temperatures that dip below 20 degrees) cause heart attack death rates to triple among men 35 to 49 years old.

Here's why: Aerobic activities, including shoveling, cause heart rate and blood pressure to rise. When the body is exposed to cold, it naturally constricts arteries and blood vessels. The combination is a recipe for a coronary event.

Winter slips and falls — which can happen when you're shoveling — are another concern.

So follow these tips for safer shoveling from the American Academy of Orthopaedic Surgeons:

[naviga:font face="ZapfDingbats"]4[/naviga:font] Cold, tight muscles are more prone to injury. Take a brisk walk for 10 minutes to warm up, then gently stretch your back, hamstrings and calves.

[naviga:font face="ZapfDingbats"]4[/naviga:font] Lighten the load. Choose a plastic, or poly, shovel that fits your height. In deep snow, remove a few inches at a time rather than the full depth at once.

[naviga:font face="ZapfDingbats"]4[/naviga:font] Divide a driveway in half by pushing the snow directly down the middle. Then clear one half at a time, pushing snow to the sides of the driveway to avoid lifting the same snow twice.

[naviga:font face="ZapfDingbats"]4[/naviga:font] Use ergonomic lifting techniques. Face toward the object you are lifting. Grip the shovel shaft with one hand as close to the blade as comfortably possible, with the other hand on the handle. Stand with feet shoulder-width apart, bend your knees and lift with your legs. Instead of flinging snow to the side, pivot your whole body. Walk to deposit the snow rather than reaching or tossing it.