Abstract: An invalid chair (10) has a seat (28) which rises (under spring or other power) at the front (36) as well as at the back (38) to assist the occupant to stand. The seat (28) is mounted by means of a mechanism (30) comprising two pairs of tracks (40,46) on the frame (12) and seat (28) respectively, two pairs of levers (50,62) forming a scissor-like linkage (76) with lever ends (52,64) carrying respective rollers (54,66) running in the tracks (40,46), and torsion springs (78) to provide the force urging the seat (28) upwardly. A latch mechanism (102) is provided to latch the seat (28) down. It can be released by a sitting occupant operating a manual device (114) under one arm (18). When the seat (28) rises, the back (38) rises further than the front (36).