I do a fair amount of crawling.
I used to live in a skyscraper (16th floor) for 5 years and I crawled all floors down in
shaolin style , before running.
Now I take steps on my runs where ever I find them. Running up, crawling down, run to the next set of stairs and so on...
Lately I started rucking and I implement some crawls with the load as well. THIS really is something different. Forward is okeyish, but backwards is really hard, though.
More practice/fight orientated with much benefits to mobility and spine health is in my opinion
Systema groundwork. Falling, rolling, twisting, getting up.
The Russian Bicycle The whole lot..