If you have trouble tipping over or falling backwards, I could give you some tips.
If you are about to fall forward, you are running too fast, or your footsteps are too small. Take 1 by 1 frame making and carefully time your footsteps. Make sure they aren't too wide, but also make sure you are still leaning forward.
If you are falling backwards, your steps are too wide. If you ever seen the Verax Tutorial, you notice that he falls forward in the beginning. It's used to gain momentum, and is very common in running styles. If your standing straight in the T position, and are about to fall back, don't be afraid to wait a few frames until you tip over gradually or just contract your hips/abs.