To build a lean physique, most personal trainers argue that you need the deadlift in your routine; after all, if it built Arnold Schwarzenegger's physique, then it's worth doing, right? Truth be told most bodybuilders--and powerlifters--make this move as part of their arsenal to build thick, lean muscle, and although you won't look like a bodybuilder just from doing this exercise, it's one of the best exercises you can do to get fit.But, of course, there are right and wrong ways to do the deadlift. The problem here is if you do the deadlift, you aren't just risking a simple strain in your knees--you risk a painful and hard-to-heal back injury.So how can you tell if you're not deadlifting right?3 Ways to Tell if You're Deadlifting WrongIf you like to deadlift but aren't sure if you're doing it right, here are three signs that may allude to bad form:1. Your back is rounding. Rounding your back to the point it resembles a drawbridge is terrible form--and if you do it too much, you're on your way to back injury city, which can take several months to heal. Instead, your back should stay as straight as possible, and should continue to stay straight throughout the lift. Note that some people do have to round their backs while deadlifting if their hip is fused, but still, the rounding should be kept to a minimum at most to avoid acute injury.2. You treat the deadlift like a squat. If you think the deadlift is just a reverse squat, you're dead wrong--and probably not practicing correct form. The deadlift is nowhere similar to a squat and involves different mechanics in order to do it properly. For instance, your hips never drop or lower like a squat, and you need to squeeze your chest upward in order to ensure you're doing proper form. Never use the squat as guidance--the squatting method is only good for squatting!3. That lower back soreness isn't actually soreness; it's acute pain! If your back is screaming in pain--like the sort of pain that debilitates you--you're definitely doing something wrong with your deadlift! Done properly, deadlifts are completely safe and do not increase your risk for injury, so serious pain is almost always a sign of bad form. Unfortunately for you, back injuries take a long time to heal, so consider this a painful (and long) learning lesson.