Photo courtesy of Elbragon.
I often hear people talking about building 'reflexive' ukemi. I used to think about deeply ingrained falling skills as more of a habitual thing than a reflexive thing. I mean - you can't build or train or create a reflex, can you? But you can train a habit.
Well, consider this. Everyone gets back pain, and often it is caused by a reflex feedback loop - a muscle gets irritated and reflexively spasms, the spasm irritates the muscle more, which prolongs the spasm. It is a vicious loop. A natural reaction is to want to stretch the muscle, but that tends to irritate the muscle more, prolonging the spasm. Some often successful therapies, like positional release, work by slacking and relaxing the muscle. On the other hand, allopathic physicians often prescribe muscle relaxers to paralyze the muscle and break the feedback loop.
Well, I have found a remarkably interesting thing that helps me when I have muscle spasms in my back. If I do a handful of rolls or airfalls, the spasm often dissipates! I think what is happening is that ukemi only works properly if your muscles are in a certain state, and when you get your ukemi ingrained to a certain point it works on a reflex level to put your muscles in that state. I guess an airfall trumps a muscle spasm, tricking your muscles into relaxing reflexly.
I wouldn't recommend this as a therapy for back pain, but it sure seems to work for me, it sure seems to be a reflex action, and it sure is interesting.