If your legs go over your center of mass in order prevent it you need to do at least three things:
1. push and flex with your shoulders over your head (shoulder flexion)
2. squeeze your glutes and abs
3. press with your fingers.
I hope this video below will clear things up.
If you are falling backwards there are at least three things you need to be doing to prevent it:
1. Move your hips forward above your head
2. Release pressure off fingers and rely on your palms
3. Lean with your shoulders forward
I hope you will find this video below helpful.
Note: I'm not a professional coach or certified trainer, I just share my own experience and how I reached my level of success. I hope you will find it helpful.
