STOPPED AFTER EXCITING FREEWAY WITH TRAFFIC FLOW. SUV CAME UP BEHIND ME AND DIDN'T STOP AND HIT ME FROM BEHIND GOING 40-60 MPH. IMPACT THREW ME BACK THEN HEADREST DEPLOYED AND PUNCHED ME IN THE BACK OF HEAD WHICH I THEN HIT SEARING WHEEL. INSTANTLY FELT PAIN IN NECK AND HEAD. TAKEN BY AMBULANCE TO HOSPITAL. 2 C.T. SCANS DONE,CHEST XRAYS, AND 2 MRIS OF NECK AND BRAIN SHOWING SPINAL STENOSIS OF CERVICAL REGION, BULGE OF CERVICAL DISC WITHOUT MYELOPATHY. I ALSO SUSTAINED A CONCUSSION AND WHIPLASH WHICH IS STILL PRESENT AS OF TODAY. CAR TOTALLED. ONE OF DOCTORS STATED IMPACT FROM HEADREST DEPLOYING WAS SAME AS BEING PUNCHED IN BACK OF HEAD FROM A 200 LB. MAN.