Put body in tension when crashing head first (somewhat like the bungee-jump body tensioning when hung by feet; but consider a design that snugs feet, legs, hip ... in order to let torso and neck and head go into tension. Avoid compressing the head and neck. There are limits to such mitigation. The helmet would be integrated into firm longitudinal beams designed to take the compression while the body "hangs" from the far end (away from headfirst impact zone.
I need a test pilot willing to be droped head first from 1m, then 2 m, then 3 m, etc. until we reach the limits of the devices; then we will need a follow-on test pilot to take the open opportunity.
The injuries can be tensional rip of tendon insertions, snapped tendons; snugging the body would be important; using some snug hold on the shoulder may be important. Such suits and device might already be developed by those being shot out of cannons or head-first sled riders, etc. Open for ideas here.
Why have a helmet that sits on the head while such adds mass to the head for advancing whiplash and not preventing compression of the neck. Rather, consider having helmet that tenses the body and tends to avoid compression of the head and neck. Still have the neck-cavity-fill torus. And in the gap G still have some foam that is giving; pure air gap is discouraged by me at this point in this unfinished designing moment.
From what I can see, my guess is that Gary Connery DID NOT employ the present idea of body tensioning via the above stated scheme.