A helmet comprises an outer shell, an impact absorbing liner inside the outer shell to receive loads from the outer shell and an inner liner disposed inside the impact absorbing liner, with the inner liner configured to slide relative to the impact absorbing liner. The inner liner defines a number of apertures and a deflector inside each aperture. Each deflector comprises: a body that is connectable to the impact absorbing liner; a peripheral border that is connectable to the aperture in which it is received; and a number of deformable spokes extending between the body and the border.