Protective clothing and/or equipment may comprise a modular helmet assembly which comprises a plurality of impact mitigation modules positioned between an outer layer and an interior layer of the helmet, optionally with a plurality of perforations or openings in an outer shell of the helmet. The plurality of impact mitigation assemblies may comprise an impact absorbing array of impact mitigation structures having at least one filament and a lateral support wall or connecting element. When force is applied to the exterior surface, the structures of the impact absorbing materials deform in a desired and controlled manner, reducing the force received by the interior layer.