I plan on mastering fingertip pushups, they impress me. I understand many people have concerns with them.
Acupuncture/pressure/chi I can’t really comment on, I don’t know anything about that, or if it applies.
As for bone structure, that is definately a big concern. I need my fingers for typing, grabbing, a lot of things. I don’t want to be grippled. That’s something to be avoided.
One thing we can probably all agree upon is that this is an advanced exercise, and should probably be supplementary to other things.
Right now, I’m working on chins/pulls (including fingertip sorta where I hold a beam), farmer’s walks, deadlifts, hand grippers and handstand. These seem like much more controlled and less dangerous forms of exercises.
Doing shrugs and wrist curls sounds good too, as well as that Formulator device, inch dumbbell, tearing phonebooks, and those Gyroscope balls they sell look very intense.
After all this, hand strengthening/hardening can come. Anyone without a master of this training them should be doing preliminary things like I mentioned to make sure they’re prepared and won’t be as likely to be injured, right?
As for how to train them, I’m not sure. Wouldn’t it make sense to try all sorts of different grips? Bridge, bent back, straight, eagle claw, and one I even though of is ON the fingernails. That’d compress your hand a lot but maybe it’d work your extensor muscles?
That’s another thing, extensor muscles. Those are really hard to figure out how to train. Real handy if someone ever grabs your hand around the fingers and tries to break them, probably.
All I’ve ever seen is rubber bands for this. One other I heard of was sticking your hand in sand/rocks packed tight (and possibly closed over) and then you open your hand and lift heavy weights that way.
I can’t help but think of some complicated apparatus of loops to go around the finger (3 per finger, to allow more weight by spreading it over the joints) and then tying weight plates to it.