So we had the first snow of the year today in Grand Rapids, MI. I can pretty much guarantee someone will come into my office next week with a sore back from improper shoveling.
Now, most people shovel in the morning. Strike one. Most people shovel by flexing forward and then throwing it off to the side, rotation, in one continuous movement. Strike two. Most people don't even think about bracing there core. Strike three. You're down for the count with back pain.
Keep your back straight. Bend from your knees and hips. Stand up after you get a shovel full of snow and then use your hips to toss the snow to the side. Two distinct motions. Don't pick up more snow then you can handle. After you get snow in your shovel. Slide your hand closer to the blade before you throw it. This will decrease the center of mass and require less core strength. Get an ergonomic handle if you can. Better yet....get a snow blower.