MONTREAL - Snow shovelling can be dangerous.

Back injuries and heart attacks are common after snowfalls, and many Montrealers got their snow shovels out early this year.

But too many people aren't careful when they shovel, according to an expert. Proper technique and a few precautions can help prevent major injuries, says David Pearsall, a professor of kinesiology and physical education at McGill University.

"It's pure mechanics when you have five or ten kilos at the end of a shovel, and you're bending your back in that direction, it puts a lot of strain on those back muscles," he said.

Pearsall suggests taking it easy while shovelling, especially if you're not used to intense physical exercise. Start small: lift only a bit of snow at a time and be careful of heavy, wet snow that's compacted.

If you're not in shape, don't do it, Pearsall urges. More people tend to have heart attacks following heavy snowfalls -- because they're shovelling snow, according to a 2017 study in the Canadian Medical Association Journal.

He also suggests using leg muscles and avoiding leaning out and bending your back.

"Try to bend your knees," he says. "It's less work on your back.  

With files from CTV Montreal's Scott Prouse