Abstract: A tilt resistor is interposed between shoulder pads or other torso support structures and a helmet. The helmet is coupled to one side of the tilt resistor and the torso support is coupled to another side of the tilt resistor. The tilt resistor acts as a pivot joint allowing the helmet to tilt about a horizontal lateral axis relative to the torso support. An acceleration sensor associated with the tilt resistor locks the tilt resistor so that the helmet stops tilting when tilting acceleration sensed by the accelerometer is greater than a desired maximum amount. The tilt resistor is coupled to the torso support, preferably through a collar, which allows rotation of the tilt resistor about a vertical axis. Stops are provided to limit both rotation about a vertical axis and tilting motion within limited ranges that are preferably adjustable.