For years, we’ve been bombarded with warnings on how to shovel snow: lift small shovelfuls, lift with your legs, not your back — that sort of thing. Now physical therapist Brett Altman offers a few new tips on freeing our driveways of flakes. First, Altman says to treat snow-shoveling like swimming — don’t shovel just after eating, or it could result in a heart attack. If your body is sending more blood to the stomach to digest food, and to the arms and legs which are working, and to your body as it tries to keep warm, it can cause undue stress on the heart. Altman is president of the Iowa Physical Therapy Association and practices at Skiff Medical Center in Newton. Altman says shovels with the weird bends in the handles are ergonomic and helpful for some people. He suggests finding the proper shovel for your particular body type. If the shovel is too short, you’ll have to bend more than you should, but if it’s too long, it’ll require more strength and leverage to lift the load of snow and to throw it. He says people between 20 and 50 are generally more likely than older people to injure their backs because they may not be aware they’re out of condition. Altman says taking rest breaks is very important when putting your body through the rigors of snow shoveling. Every ten or 15 minutes, he says to do a standing extension exercise: stand up straight, put you hands on your hips and bend backwards for ten or 15 seconds. Altman says do not shovel in the morning — wait until afternoon — as many back disc injuries happen in the morning when there’s increased fluid pressure in the disc, as you’ve been laying down all night.