Snow Shoveling Alert!
The one most important factor to prevent back injury when snow shoveling, is to occasionally switch sides. When shoveling right handed, the muscles on the right side of the low back are used more than the muscles on the left side. You can actually feel this while shoveling. Switching to the left side now works the muscles on the left side of the low back. If you were to just shovel on one side only, you risk having the muscles on that side eventually pull the vertebrae out of alignment, which results in nerve root pressure and low back pain. Switching sides, balances the pull of the muscles on both sides, resulting in far less chance of pulling the vertebrae out of alignment.