Workstation design & layout should accommodate several factors:
Workstation Height: Correct work station height depends upon the user of a work station and upon the chair and other factors that interact with the user and table. The ideal is for the user to be able to sit at the work station with the keyboard in place and be able to easily maintain a 90-100 degree elbow angle and straight wrists while keying. The height of an adjustable keyboard support should adjust between 23″ and 28″ to accommodate most-but not all-users. 26″ is a recommended compromise position while leg clearance must still be considered.
Leg Room: Knee spaces should allow a worker to feel uncrowded and to allow some changes of position even with the keyboard support lowered to the correct level for use. The knee space should be at least 30″ wide by 19″deep by 27″ high to comply with the requirements of the Americans with Disabilities Act. For those using a footrest, clearance must be calculated with the legs in place on the footrest. Likewise, depth of the “clearance envelope” for both legs and toes should be evaluated while the workstation user is in a normal working position at the work station (determined by the design of the seating system and the way the user sits). Drawers and support legs (for furniture) should not go where human legs need to fit.
Workstation Surface: The workstation top should be big enough to allow space not only for all computer-related necessary equipment, but also for paperwork, books, and other materials needed while working at the computer. Working with materials on chairs and at odd angles has the potential for neck and other body strain. Frequently used items should be kept close to avoid long reaches. A general recommendation is that the work area top should be at least as big as the standard office desk – 30 inches by 60 inches. A depth of at least 30 inches allows flexibility in use/reuse of the work area. Usable space may be maximized by good wire/cable management.