One of the easiest ways to injure your back is through careless lifting. A proper lifting technique looks a bit like the squat exercise. Like the squat, it involves crouching down and using the strong muscles in your legs to do the brunt of the lifting, minimizing the stress you put on your back and reducing the amount you bend your spine. A little preparation can make all the difference in proper lifting. Before you grab the object in front of you, adopt a wide, crouched stance. Make sure your feet rest firmly on the floor and that your back is straight, not hunched. Stand slowly, avoid twisting to the side, and concentrate on pushing with your legs, rather than pulling with your back.
If you struggle with back pain, experts will tell you to use proper lifting for any object below waist height—even a dropped pencil.
Source of Information : Oreilly - Your Body Missing Manual