The exercise apparatus includes a table having a longitudinal dimension; a set of rails disposed longitudinally on opposite sides of the table; a set of posts on opposite sides of the table adjustably supported on the rails for longitudinal movement along the rails and for vertical movement extending...http://www.google.co.uk/patents/US4226415?utm_source=gb-gplus-sharePatent US4226415 - Universal exercise apparatus for performing hamstring flex and other exercises
