I STEPPED OUT OF THE RENTAL VEHICLE, 2019 DODGE CARAVAN, AND LIFTED THE LEVER OF THE RIGHT CAPTAIN SEAT TO LET MY CHILD IN THE THIRD ROW OUT. THE CHAIR SNAPPED FORWARD WITH TREMENDOUS AMOUNT OF FORCE. WHILE I WAS PULLING THE LEVER WITH MY LEFT HAND MY RIGHT HAND WAS PLACED ON THE SEAT BACK. THE FORCE PULLED MY HAND IN AND UP AND PINCHED MY FINGER IN THE HINGE OF THE THEN FOLDED HEAD REST. MY RIGHT PINKIE WAS SLICED AND ALMOST SEVERED OFF. IT REQUIRED 4 STITCHES AND COULD HAVE A POSSIBLE FRACTURE. THE VEHICLE WAS STATIONARY AT THE TIME.