From The Ergoweb® Learning Center

Ergonomics- Computer Workstations

Task Prior to Abatement (Description)

An ergonomic case study for computer workstations.  Petroleum Technology Center (PTC) is Marathon Oil Company’s technology and field-operations support facility. It has 227 employees and is comprised of engineers and scientists. Tasks performed by employees include usage of computer workstations from half an hour to eight hours per day with an average of four hours per day. Employees ages ranged from 20 to 64 years with an average age of 43.9 years and range of service from up to 37 years with an average length of 14 years. The majority of tasks became computerized during the early part of 1993. Following the computerization of the tasks the workforce was down-sized, thus requiring more work to be accomplished by fewer workers. These two factors were thought to be contributing to an increasing number of CTD related injuries.

Task Prior to Abatement (Method Which Verified Hazard)

Workers compensation records (OSHA 200 Logs) verified the increasing number of CTD related injuries

Task Prior to Abatement (Method Which Identified Hazard)

  • From 1990 to 1993 number of injuries increased from 1% to 3% of the total employees.
  • By 1993, 77% of the injury claims were CTD related injuries.
  • Medical claims increased from 10% in 1990 to 13% in 1991, with a high of 18% in 1992.
  • 83% of the total medical costs by 1993 were CTD related.

Ergonomic Risk Factor (Posture)

Awkward posture was required to perform the tasks.

Ergonomic Risk Factor (Repetition)

Performing the tasks using computer workstations require repetitive motions.

Ergonomic Solution (Administrative Controls)

  1. Employee education was comprised of lectures in ergonomics issues.
  2. Advanced training – the trainer program for ten employees in order to provide in-house ergonomics advisors to coworkers.
  3. Emphasizing exercise breaks every half-hour for five minutes.
  4. Providing educational materials in pamphlets and wall posters.

Ergonomic Solution (Engineering Controls)

  • Lowering work surfaces
  • Adjusting chairs
  • Purchasing new adjustable chairs.
  • Adding/Adjusting foot rests and wrist rests.
  • Changing the location of computer terminals.
  • Purchasing articulating keyboard trays, wrist rests, mouse rests, foot rests, glare screens, document holders, task lights, and lumbar back supports.

Ergonomic Solution (Benefits)

  • All workers that currently perform the tasks have reduced exposure to all kinds of CTDs.
  • Positive feedback by employees.
  • Increasing awareness of computer related ergonomics issues.
  • Positive effects on the work environment.
  • Positive cost outcomes for the company.

Ergonomic Solution (Cost)

The total cost of the project was $44,000. $39,000 was spent for new chairs and equipment and $5,000 for a physical therapist/ergonomic consultant.

Ergonomic Solution (Method Which Verified Effectiveness)

  • CTD claims decreased to zero. ( There were no new CTD claims after the implementation of the ergonomics program and all of the previous cases have now been closed ).
  • 80% reduction in workers’ compensation costs.


The success of the program resulted from manager support, surveying employees needs, and relying on employee involvement to keep the program going.


Cook, Oma Jo, and Pinelli, John A., 1995, The Effects of a Comprehensive Ergonomic Injury-Prevention Program with an Emphasis on Employee Ownership, For Keyboard Users, Advances in Industrial Ergonomics and Safety VII.