A previously developed prototype of multi-position ergonomic computer workstation, which had 19 Degrees of
Freedom (DOF) actuated by seven linear actuators, was used as a test equipment. Positions of the workstation were
controlled by changing strokes of each actuator in different stroke combinations. These actuators with mechanisms
changed the position of the workstation parts, which are the headrest, backrest, seat, armrest, footrest, monitor and
keyboard, to get a required working position. The actuators had a different velocity and the positions were
controlled separately. A control panel was assembled on the left hand armrest for easy access at the tip of fingers.
The actuator and the control switch were connected to the control box. The control switch had two switches for
extension and retraction motion of each actuator. Each actuator had its own control switches on the control panel
and they were controlled separately. The workstation could accommodate from 5th percentile female to 95th
percentile male human size.
The workstation was designed to have multiple positions from lower limit of leaning forward to upper limit of
leaning backward. However, four different working positions were selected for this evaluation. These preset
working position were chosen for their different features and speculated ergonomic advantages as stated below.