I registered so I could reply to this.
I've raced and cruised offshore several thousand miles, some of it single-handed and did the same in the Pacific Northwest inland salt waters for years. I've been there when boats hit rocks, logs and sand bottoms.
I would never sleep head-forward. You can make all the silly hypothetical arguments you want, but I'd prefer to risk having my feet slammed against the bulkhead than my head.
I feel honored that you registered so you could add to my little thread. Thank you for your comments. Welcome aboard.
I'm in agreement with the group that says that the risks are very low. I've personally never heard of a spinal injury on a sailboat due to sleeping head forward.
The alternative for most boats is very simple just sleep head forward. It's not like I'm recommending something ridiculously hard like always wearing a life-jacket (which I also do by the way).
We all make dozens of judgement calls while on the land and on the water every minute.
Look both ways before crossing the street.
Wear a condom
Is my head low enough to clear the boom.
Check the paper chart to confirm what I think the gps is saying.
Throw the pillow to forward or aft on the bunk
The list goes on and on, what is one more minor consideration.
I think that the difference between people that are "lucky" and people that are "unlucky" is that the "lucky" ones make hundreds of very small, maybe unnoticeable choices not out of fear but because they have a habit of visualizing events.
That visualization causes them to subtly change the way they handle lines, walk on the deck, navigate everything.
These subtle changes never matter 99.999 percent of the time.
But rare events happen much more often than we expect.