Rethink your ukemi

http://www.mokurendojo.com/2007/11/at-risk-of-being-called-heretic.html
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Look for the large subsets of aiki that you can do with uke responding by kneeling down or sitting back into a gentle backfall. Emphasize these subsets and all of a sudden you have an extremely viable, practical self-defense system that virtually anyone can learn rapidly (months - not years), comfortably, and in greater safety without the need for large open spaces and matted floors.
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