WIFE INVOLVED IN A REAR END COLLISION. HER VEHICLE WAS STOPPED. UPON INPACT THE DRIVERS SEAT BACK FELL ALL THE WAY BACK, SHE SUFFERED A CONCUSSION AND WHIP LASH INJURY AND WAS TRANSPORTED TO CHELSEA COMMUNITY HOSPITAL. THE SEAT BEING IN THE DOWNWARD POSITION WAS POINTED OUT TO THE STATE POLICE AND EMS PERSON BY MY WIFE. THE VEHICLE WAS TOWED TO MY HOME, SEAT PHOTOGRAPHED IN DOWNWARD POSITION. WHEN SEAT IS RAISED IT WILL NOT STAY IN PROPER UPRITE POSITION, IT GOES BACK AT APPROX 45 DEGREE ANGLE AND TWISTED BACK ON RT SIDE. CONTACTED GENERAL MOTORS, THEY SAY THAT THE SEAT CONDITION DID NOT CAUSE THE ACCIDENT SO THEREFORE THEY ARE NOT RESPONSIBLE.*AK