USER DESCRIBED EVENT AS FOLLOWS: "I WAS USING THE MYSELF BIOFEEDBACK DEVICE ACCORDING THE DIRECTIONS. THAT IS PUMPING AIR INTO THE SENSOR UNTIL THE LCD DISPLAY TELLS ME TO STOP. THEN TIGHTENING MUSCLE UNITL THE BIOFEEDBACK DISPLAY TELLS ME TO RELAX. WHEN DOING THIS I FELT A SUDDEN PAIN AND TWINGE. A LUMP PROTRUDED LOW ON MY ABDOMEN. I HAVE SEEN A DOCTOR ABOUT THIS, IT IS AN INGUINAL HERNIA."