Molly Gelbraith and Jim Laird talk about creating a braced neutral spine to avoid lower back over extension.
To really get into a stable position I really like Kelly Starrett’s 4 step bracing sequence as outlined in chapter 1 of the Supple Leopard book:
- Squeeze your your butt as hard as you can (set pelvis in neutral)
- Pull your ribcage down
- Get your belly tight
- Set your head in neutral position and screw your shoulders into a stable position (externally rotate)
Anyway, here is their video.
How To Get Braced and Avoid Lower Back Hyperextension is a post by Gregor Winter from All Things Gym.