Slapping the ground during ukemi.
In bujinkan I was taught not to slap and to take the fall with your body, or use the legs. (sorry, can't explain verbally how to do it.) In the judo and BJJ circles slapping is the standard procedure for ukemi. I am taught to slap in BJJ when being taken down like this:
but so far I have not noticed any significant difference, which makes me tend towards not slapping. Only one time I felt it helped when someone caught my kick and launched me backwards during bujinkan, I instinctivly did a double slap when my back hit the gound and it felt like it helped soften the fall. Like this:
(The instructor joked about it as the bujinkan sensei out there take a dim view of slapping.) During wrestling (through my shooto and grappling classes) no mention has been made of slapping, IIRC I don't believe wrestlers slap.
What are people's views on the slap vs no slap? Has anyone here had the chance to compare? Is there any evidence that favours slapping? What about lava?
We do have this one in the bujinkan, it is sort of a slap.