An integrated approach to the study of posture in keyboard operation

An initial survey showed that typists tended to work with their keyboards higher than is normally recommended in the ergonomics literature and to report discomfort in the shoulders, neck and upper back. An experiment was conducted in which biomechanical stress, subjective comfort and typing performance were evaluated with respect to keyboard height and the presence or absence of a copy stand. Increased keyboard height resulted in increased postural torque about the shoulder joint, decreased torque about the C7 vertebra, and increased discomfort. Keyboard height had no effect on typing performance.