Avoid any sudden strain. If you are going to have to bend in any way make sure that your back is not cold and stiff.. Stretching your back helps loosen it and prevent injury.If you sit for long periods, make sure your back is properly supported. Place a small roll in the arch of your lower spine (at waist height) to maintain its normal S-curve. Simply a towel, or cushion rolled up will do. further tips view: http://www.nikhar-e-arab.com/backacheprevention.html