EMPLOYEE WAS A PASSENGER IN THE OUT BY END OF A MANCAR, A PARKING MECHANISM FELL FROM ITS HOLDER TO THE MINE FLOOR CAUSING THE OUTBY END OF CAR TO RAISE ABRUPTLY WHILE DERAILING THE FRONT END OF THE MANCAR. EE'S MOMENTUM AND ITS ABRUPT RAISING AND LOWERING OF THE MANCAR RESULTED IN THE EMPLOYEE'S FALLING ONTO THE EDGE OF THE BACK REST STRIKING THE CENTER OF HIS BACK.