Shoveling snow is a common cause of a new back injury OR aggravating to an already existing back injury. The following tips may help you avoid injury or aggravation to your back.

The Right Shovel - Use a shovel with a curved and adjustable handle. This can reduce the need for painful bending. You may want to try a lightweight plastic shovel to help reduce the weight of the shovel.
Warm up - Before you start shoveling do some warm-ups before going out, cold tight muscles are more prone to injury than muscles that have been exercised.
Take your time - Remove small amounts of snow with frequent rest stops. Do some stretches during your rest to keep your muscles loosened up. When possible do your shoveling over a period of days not all at once.
Snow blower - If possible use a snow blower and use your legs to propel it not your upper body.

Better yet, get someone else to clear your driveway!

Be careful and be smart and your back will thank you for it!