Work Station Layouts-Environmental Health & Safety - Carnegie Mellon University

Work Station Layouts

While employees are not required to order ergonomic furniture or equip their office with ergonomically friendly equipment, it is encouraged. Guidelines are offered for the following:

Guidelines for Desks/Tables

  • Monitor and keyboard platforms should be independently adjustable. If this is not possible, the keyboard should be placed on a keyboard tray that can be adjusted for height, angle, and horizontal positioning.
  • Front edge (where keyboard would be placed) should not have any sharp edges. 
  • Foot rests and wrist rests should be available.

Guidelines for Chairs

  • Chairs should be adjustable, including adjustment for the backrest, with an adjustable tilt and backrest angle.
  • Adjustments should be pneumatic or hydraulic, rather than mechanical, for height adjustment. 
  • The backrest should be able to be locked into one position when desired. 
  • The chair should have five legs for maximum stability, 360° swivel, and a waterfall, or rounded, front to minimize pressure on the underside of the legs. 
  • The chair must have good back support. Seat tilt should move forward, as well as back, to provide back support if leaning toward the monitor.
  • Chairs should be equipped with armrests that are wide enough and soft enough that there is no unnecessary pressure imposed on the forearms.
  • The armrests should be adjustable, preferably in all directions. 
  • Material should be non-sliding and breathable (no plastic or vinyl).
  • There should be a 1” – 3” clearance between the front edge of the seat pan and the back of your knees when you are sitting comfortably with your back against the backrest and your feet flat on the floor.

Guidelines for Monitors

  • Monitors should be adjustable for height and angle, to avoid neck discomfort and to control glare. 
  • Placement should be directly in front of the user. 
  • Monitors should be positioned so that light from windows comes in from the side. Overhead lights should run parallel with the computer user’s line of sight. (Where this conflicts with proper window positioning, it is usually easier to control window light with blinds, and the overhead lights become the condition for which monitor positioning is crucial). 
  • Monitor elevation should be such that the eyes are directed to the top of the screen, or just slightly below, when looking straight ahead.

Keyboard/Mouse

  • The mouse should be sized so that it fits the user’s hand comfortably.
  • The mouse should be immediately beside and at the same level as the keyboard. Where keyboard trays are used the tray must be large enough to accommodate both the keyboard and the mouse.. 
  • Generally, the legs at the back of the keyboard should be kept retracted, to avoid excessive bending at the wrist.

Body Position and Work Habits

  • The mouse should be moved from one side to the other on a weekly basis, to maximize recovery times. 
  • If soreness develops in hands or forearms, reduce typing speed. If there is no improvement within a few days, get an evaluation to determine if other factors are involved. 
  • Chairs should be positioned so that there is a 90° angle at the knees and at the hips. Footrests should be available for those who can not meet these angles. Something as simple as a box may be used, although it should be replaced as it depresses. 
  • Keyboards should be positioned so that there is a 90° angle at the elbows without shrugging the shoulders. 
  • The chair, keyboard, and monitor should be placed directly in line with one another so that there is no neck rotation necessary to view the monitor. 
  • Placing the monitor at the inside corner of two adjoining surfaces should be avoided unless accommodations are made for the keyboard and mouse.
  • Monitor screens should be kept clean and dust-free, to minimize glare. 
  • Users can minimize eyestrain by remembering to blink regularly when working at the monitor, and by regularly (every few minutes) looking at a distant object for a few seconds to vary the eyes' focal lengths.
  • Desk exercises are helpful and recommended.
  • Computer users should work no longer than one hour at a time before taking a short (5 – 10 minutes) break. Break reminder software can be used if you have difficulty remembering when to interrupt your work routine. A free program can be downloaded from http://www.cheqsoft.com/break.html. 
  • Wrists must be kept straight in both the horizontal direction and the vertical. It may be necessary to use a wrist rest to prevent the wrist from dropping below the neutral plane. However, do not rest your wrists on the rest continually.

General/Miscellaneous

  • Window blinds should be in place for control of glare and brightness. 
  • Adjustment mechanisms must be fast and easy to activate, or they will not be used. 
  • Small lamps, or task lighting, may be placed on desks to facilitate reading, but must be placed so that they do not produce screen glare. 
  • If users will be doing a lot of typing from documents, manuscripts, etc., document holders should be used. They should be placed immediately beside the monitor so as to reduce head and neck movement.
  • At least a few of the work areas in multi-user offices should be wheelchair accessible. Adjustability will be especially important in these areas.
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