Re: Ueno Chimp Rolls
Good call with ressurecting this, Hannah.
I think ultimately I need to get the Ground Up video.. but the conversation is still great in the meantime, and my brain has been able to put this information together better today, just from re-reading this.
What do you guys think, here's what I am starting to think based on the info here, especially Charles' description, Joep's reply to me, and Eugene's caveats:
When you roll, you spread impact across the whole path of the ground-body contact spot-- but the first moments of contact take more force than the rest. (Impulse is greater in the first half of the roll then the 2nd.) If you have a big vertical drop (threshold for "big" depends on how hard your surface is) then you want 2 things: keep the point-of-contact's spinal crossing confined to the 2nd half of the roll, and minimize time of contact with shoulder region. Result = Ueno chimp roll.
If you on the other hand you have low fall height, possibly with significant sideways momentum (or use your outstretched arm for sideways traction like the Russion guy), then you have another good (best?) option: you use the scapular "drawbridge" to get the point of contact across the spine with protection. So the upper pelvis area and lower back don't bear much, or do much work. Result = the russian roll.
The midpoint-crossing roll being criticized here ("aikido roll") is a compromise/mix of the strengths of these 2, but has significant problems that are particular to it-- particularly dealing with the stressful and strength-intensive arm-to-shoulder portion of the roll.
A lot of thinking.. but ultimately I think I want to go out and play with these and feel what they are each best for..