Wrist motions and fingertip loads when operating joysticks in a simulated forest machine cab

Results of experiments are described in which an operator uses joysticks in a detached forest machine cab. The motions of the joystick and wrist are measured along with the loads under the tips of the fingers. Finger forces are found to be lower than expected with tight grasp applied only when pulling back on the joystick. The required ranges of motion of the wrist are found to vary substantially to achieve different joystick orientations. These may have an influence on how to arrange controls to minimize repetitive loads on the wrist