I know this sounds overly simplistic but the cue I use for your problem is "feel like your keeping your feet behind you." Another thing to consider is that you're not pushing hard enough while you are in contact with the ground. The initial steps should be really long hard pushes. If you're just tip-tapping down the track on your first couple steps without really pushing you probably aren't generating the flight time necessary to get your feet back under your body. As a result, you'd end up contacting the ground early and in front of your body.