The present disclosure relates to a cushion for use in a helmet comprising an outer shell for impact with an incoming force, the cushion disposed between the outer shell and a head when the helmet is worn, the cushion comprising: a sealed bladder comprising a flexible membrane; a pad housed within the bladder, said pad comprising a compressible member having interstices open to the exterior of the pad; and a liquid within the interior of the bladder; wherein said pad absorbs at least some of said liquid when uncompressed and expels said liquid when compressed; and wherein the volume of liquid within the bladder is sufficient to allow opposing surfaces of the bladder to be displaced in a shearing motion relative to each other when the cushion is compressed and subjected to shear forces, to decouple shear forces between said helmet and the head.