Abstract: An apparatus can include a seat, a backrest, a base frame comprising wheels and an adjustment assembly. The adjustment assembly can be adjustable from a lowered position to a raised position. The adjustment assembly can include an actuator assembly, pairs of scissor legs, and a connector. The actuator assembly can include: an actuator positioned underneath the seat, where the actuator comprises an actuatable shaft; and biasers positioned underneath the backrest. In addition, the connector can be attached to the pairs of scissor legs and the actuatable shaft, the connector being configured to: compress the biasers upon extension of the actuatable shaft away from actuator; and decompress the biasers upon retraction of the actuatable shaft towards the actuator.