I have got diabetes lupus knee problems and kidney problems from the lupus i have had knee problems since i was 11 i did do karate and had to give it up so three or four years ago i joined aikido i am now a 5th kyu which i just passed on the 8th july 03 i can't do some moves because my doctor has said so i don't do shikko or tenkan on knees i can just about do hammi handachi shionage (iriminage)i do find it quite hard but i still keep on going i do thursday and sat ladies class.