Disclosed is a protective helmet and a method for mitigating or preventing a
head injury, in which a shock-absorbing, or shock-absorbing and comfort-providing, inner wearing unit, which can comprise liners, comfort pads, protective pads, nubbed cages and / or strapped wearing units (for example spider-shaped wearing elements, wearing straps, head bands or the like), is divided into a shell-side insert and a head-side insert, which can be counter-rotated (preferably starting from application of a predetermined force) in at least one direction, wherein a sliding surface is provided that assumes the function of a rotational surface, so that the
angular acceleration introduced by a blow is drastically reduced or prevented because the head-side insert and the shell-side insert, and thus the head of the wearer and the outer helmet shell, can be counter-rotated quickly and without impediment, preferably in all directions.