If you ever spent time in the weight room, you probably heard someone say that you should lift with your legs, not with you back. And they’re right. While some lifts do put pressure on your back, you want the focal point of the lift to rest on your legs. They’re stronger, they’re more stable and the odds of injury are far lower.

This idea extends outside of the weight room, of course. Health experts note that most people who try to pick up a heavy object — a box in a warehouse, a mattress in a hotel, a set of weights at the gym — get hurt because they use improper technique while lifting. It’s often not even that the item in question is too heavy. They can lift it. They just bend at their back and lift with their spine, leading to injury.

Back injuries can be severe. You may have no symptoms and no issues, make one ill-advised lift with poor form, and damage it so badly that you can barely get out of bed. Even after you see a doctor and recover, you may be more likely to injure it again. The injury can also have a psychological impact, making you worried to do any physical labor because you think you’ll get injured yet again.

For workers who have to lift heavy objects as part of their job, though, the risk of a back injury is constant. It can happen even with proper technique. If you get injured on the job, you absolutely need to know about all of the rights that you have.