First thing which should keep in mind is to prevent Back Strain or Pain is that we should wear Flat Shoes with Low Heels (1 Inch or Lower).
Another thing we should do is to exercise regularly because an Inactive lifestyle contributes to lower back pain.
We should take proper sleeping positions.If you sleep on your back,put pillows under your knees and a small pillow under your lower back.Do not sleep on stomach unless u put a pillow under your hips.
Some more tips on this will be more helpful to you.
Push rather than pull when you are going to move heavy weight objects.If you must sit at your desk for long hours ,break up the time with stops to stretch.Do not lift any heavy objects y bending over.Lift the object by bending on your knees and squatting to pick up the objects.Keep your back straight and hold the object close to your body.Also avoid twisting your body while lifting.