A headrest for mounting on one or more vertically extending posts positioned on the backrest of a vehicle seat, the headrest comprising one or more mounting sleeves positioned on the headrest and adapted to surround a portion of a respective one of said posts, pivot means extending between each mounting sleeve and the respective post to mount the mounting sleeve on the respective post in pivotal relation thereto about a pivot axis substantially transverse to the longitudinal axis of the post, each mounting sleeve being shaped and otherwise dimensioned on an internal surface to resist pivotal motion of the headrest between first and second positions below application of a directed threshold force to the headrest.