Computer Workstation Evaluation & Adjustment

WHY IS PROPER ADJUSTMENT IMPORTANT?

Today most businesses rely on computers, and employees are spending more and more of their time in front of them. As a result, injuries and illnesses associated with computer use are on the rise, including carpal tunnel disorders, eye strain, headaches, and back pain. Most of these injuries can be prevented if the computer workstation is properly adjusted and maintained.

Oftentimes companies assume that buying new furniture and workstations will alleviate their ergonomic exposures. These companies find that buying new, ergonomically designed equipment, can be very expensive and may not prevent injuries. Though buying new equipment is one part of the solution, two other parts must also be considered:

• Existing equipment could be satisfactory if properly adjusted.
• New ergonomically designed equipment will not solve the problem unless it is adjusted properly, employees know how to adjust it, and it is maintained.

HOW TO EVALUATE COMPUTER WORKSTATIONS

Observe - The best way to determine how an employee utilizes the workstation is to observe the employee at work, noting actions that may cause injury.

Discuss - Ask the employee to discuss the tasks performed, how equipment is utilized, and any concerns or complaints.

Identify Equipment Restrictions - Determine which workstation components are adjustable and which ones are not.

Take Measurements - To assure that the workstation is properly adjusted, first take three basic measurements of the employee.

OPERATOR MEASUREMENT

To take the measurements, seat the employee on a desk or table with the back of the knees just touching the surface edge. The employee should sit up straight, but comfortable, with arms down and elbows bent.

Knee Height (A) - Knee Height determines proper chair height and is estimated by measuring from behind the knee to the bottom of the heel of the shoes usually worn.

Elbow Height (B)- This measurement determines proper keyboard height. Measure from the tip of the elbow to the tabletop.

Eye Height (C) – This determines the correct VDT height. Measure from the eyes to the top of the table or desk.

ADJUSTING COMPUTER WORKSTATIONS

Once the measurements are taken, the components of the workstation can be adjusted. In most cases, the chair is the first component adjusted because the other heights are contingent upon it. In some cases however – i.e. keyboard or VDT height not adjustable – other components will have to be considered first.

Chair Height – Adjust the chair height so that the seat pan is equal to the Knee Height (A) measurement. Remember two things:

• If the seat pan drops when someone sits in the chair, then the proper adjustment is Knee Height (A) plus the amount the seat drops.
• If the chair cannot be adjusted low enough for the operator, provide a footrest. The chair height should then be equal to the Knee Height (A) plus the height of the footrest.

Keyboard Height – The keyboard should be positioned so the forearm is horizontal and the wrist is straight. To accomplish this, the Home Row of the keyboard height should be equal to the Knee Height (A) plus the Elbow Height (B). A padded palm rest may still need to be provided to prevent the palm from resting on the corner of the desk.

VDT Height – The top edge of the VDT should be slightly below the Knee Height (A) plus the Eye Height (C). When positioning the VDT, four other aspects also need to be addressed:

• The VDT should be at last 16-24 inches away from the operator.
• The VDT may need to be lowered if corrective glasses are worn.
• The VDT should be positioned to reduce glare.
• If the operator reads a great deal while at the computer, position the VDT to one side or the other and incorporate a document holder in the workstation.

ADDITIONAL THOUGHTS

Though the workstation components listed above are the most likely to contribute to discomfort, there are a few other areas to consider as well:

Computer Mouse – The computer mouse should be positioned directly next to the keyboard. The mouse should operate correctly and roll on the pad easily. This is especially important for those who use the mouse constantly.

Lighting – In areas where computers are in constant use, general office lighting should be kept lower. This will reduce glare, and make the VDT easier to see. If the operator is required to read, task lighting should also be incorporated.

Employee Posture – Employees may still suffer ergonomic injuries due to poor posture. Here are some tips: keep head and neck upright, keep wrists straight and forearms parallel with the floor, support lower back, and keep feet flat on the floor.

Employee Work Habits – Some tips: use document holders, keep frequently used items within easy reach, and pace work.