Whether you work outside pushing a mower or in a cube pushing paper, your back can take a beating. Who has time to remember to lift heavy objects the proper way, practice good posture when you sit, and get up to walk around every half hour or so (or take a break if you’re on your feet all day)? And if you have a few extra pounds, that only makes things worse. Back pain costs employers more than $7 billion a year. To Prevent It: Use your legs to lift, watch your posture, and always ask for help if something is too heavy or awkward.