This move is not only a great squating position but a great stretch too. Make sure your back is flat, heels are planted, knees aren't going over the toes and you aren't tucking your bottom. Try to hold for 30 seconds or more.
We use to squat so much more (back in the days when we had to go potty outside). There are studies that show that they didn't have the issues birthing their babies or with weak pelvic floors (i.e. incontinence) like we do now. When we squat, we work the butt muscles that keeps us from tucking under and creating a smaller pelvic area (we wanted a larger pelvic area so we can give birth easier). This also helps tighten the pelvic floor and keep from incontinence. We all don't want that!
Please read this AWESOME article here at Mama Sweat Blog- it explains all of this much more throuroughly.