Its one of the most effective exercises I know - or at least that's what everyone claims. I have been using this as a part of my program for the last 2 years. However, I always end up with a sore lower back whenever I try to lift more than body weight, no matter how much I work on my form.
Well that all changed today after I tried this technique courtesy of "Double Your Gains". I can't believe they are giving out this information for free.
The key, once again, is to push outwards with your knees, while making sure that the weight is on the heels. This activates the hips and glutes and lets you lift more without putting too much pressure on your lower back. Amazing stuff!