HAD SURGERY ON LEG SO WAS SITTING IN BACKSEAT BEHIND THE PASSENGER SEAT. I WAS SITTING SIDEWAYS TO KEEP MY LEG ELEVATED. WHEN WE ARRIVED AT OUR CABIN AND THE CAR WAS PARKED....I SPUN AROUND TO NORMAL SEATING POSITION TO REMOVE THE SEAT BELT AND GET OUT OF THE CAR. HOWEVER, THE SEAT BELT TENSIONER KEPT GETTING TIGHTER AND TIGHTER WITH EACH MOVEMENT I MADE. I WAS THINKING THIS IS CRAZY..THIS CAN'T BE HAPPENING..IT HAS TO EVENTUALLY RELEASE THE TENSION. IT DID NOT. IT KEPT GETTING TIGHTER UNTIL I WAS PINNED INTO THE DOOR JAMB WITH IT STRANGLING ME AROUND MY NECK. MY PARTNER HELPED PULL IT DOWN OFF MY NECK WHILE I HELD THE SEATBELT FROM TIGHTENING FURTHER. HE THEN RAN INTO THE CABIN AND GRABBED A PAIR OF SCISSORS TO CUT ME OUT. I AM A 220 LB FIT SHAPE 6'-2" TALL MALE.