Luci Krippner's eyes never leave the little white ball as her arms loosen up. When she plays ping-pong as she is today, in Berlin, she can forget for a while that she has Parkinson's disease. Since last year, Krippner has been training twice a week with a dozen members of the "Ping Pong Parkinson" association, which promotes what it calls the therapeutic virtues of the discipline. On April 11, World Parkinson's Day, the players were all in, relentlessly pounding the ball across the short net in a sports hall in Berlin. "I forget it" says Krippner, "I train sometimes for three hours without realising I'm tired". The group's coach, Andreas Moroff, explains "you don't think about your Parkinson's disease at all while playing." IMAGES AND SOUNDBITES