Abstract: An aid for visual detection of a golfer's head movement, constructed of card or plastics sheet, includes a black-faced sighting member (2) that has a circular aperture (14) therethrough and is hinged to a base member (1). Adjustment of the inclination of the sighting member (2) to the base member (1) brings a black disc-marking (15) line sight (L) through the aperture (14). Lugs (8) of a stay member (3) which is hinged to the sighting member (2) for setting the sighting-member inclination, are held engaged in selected notches (10) of the base member (1) by a sprung-up tongue (12); in an alternative form of aid a stay member (23) engages in transverse slots (26). Head movement is observed as apparent movement of the disc-marking (15) within the aperture (14).