thanks all you caring people who responded to my plea fortunately, i did not slip a disc! but i thank the exercise instructor who sent me to the hospital - better be safe than sorry! i must have pulled a muscle or severely strained it or something and i also thank the ER doctors and the pharmacist who kept me waiting an extra four hours before letting me go - while they checked and rechecked that the medication they prescribed did not react with my PD meds! thanks, guys! hilary blue