DRIVERS SIDE SEAT BACK BROKE DURING A CRASH FROM BEHIND. CAUSED INJURY TO DRIVERS HEAD, NECK AND BACK. LEFT SIDE OF DRIVERS HEAD HIT DIVIDER POST BETWEEN DOORS, DRIVERS NECK WAS ALLOWED TO SNAP BACK, AND DRIVERS BACK WAS ALLOWED TO TWIST WHEN SEAT BACK BROKE AND DRIVER WAS THROWN DOWN INTO REAR SEAT AREA.*AK