Detection of a fall of a user wearing the device. A processor is configured to time sample and to input multiple values over time of: the acceleration vector, the angular velocity and the point-to-point distance. The processor is configured to determine over time the direction of gravity from the acceleration vector. The processor is configured to integrate over time the angular velocity to produce an orientation angle of the protection device relative to the direction of gravity. The processor, responsive to the point-to-point distance and the orientational angle, is configured to determine heights over time of the distance sensor from the ground. The processor is configured to indicate initiation of a potential fall event by a change in downward acceleration measured by the accelerometer or a rapid decrease in the determined heights of the distance sensor from the ground. The processor is configured, responsive to the point-to-point distance and the orientation angle, to determine at least one height before the initiation of the potential fall event and at least one height after the initiation of the potential fall event of the distance sensor from the ground.