Coach mentioned this elsewhere, but you can elevate the body (on panel mats or similar) so that the hands are on the floor significantly below the body (6-8" or so)
Also, arch rocks might be helpful
Chest Roll - HeS too difficult. How to modify?
Started by Aaron Griffin, September 23, 2011 · 2 Replies · 2,469 Views
You can also try going HeS to chest as slowly as possible.
The negative is much easier. If you don't have panel mats or the equivalent you could also use a gymnastic ball.