Yes, we know you've done a lunge beforebut are you sure you're doing it right? This move is a low impact body-weight move that tone your butt, hips, and thighs, but doing them wrong can be bad news for your body. Watch Health contributing fitness editor, Kristin McGee demonstrate how to do this move perfectly, so you can tone your entire lower body while staying healthy and pain-free.

RELATED: 18 Exercises to Tone Your Butt, Thighs and Legs

Here’s how to do it: Stand tall with your feet hip distance apart with toes pointing forward, keep your core tight and your back straight. Then, step your right foot forward about two feet, lower your body so that both legs make 90 degree angles and push off with your right leg to return to the standing position.

Trainer tip: Common knee-busting mistakes include letting your knee extend beyond your toes and letting your back knee hit the floor. Remember to keep your front shin straight and have your back knee hover a few inches above the ground to prevent injury.

Try this move: Perfect Lunge 

RELATED: 10 Exercises for Healthy Knees