Situations in offices that can lead to injury or illness range from physical hazards (such as cords across walkways, leaving low drawers open, objects falling from overhead) to task-related (speed or repetition, duration, job control, etc.), environmental (chemical or biological sources) or design-related hazards (such as nonadjustable furniture or equipment). Job stress that results when the requirements of the job do not match the capabilities or resources of the worker may also result in illness.

A well-designed office allows each employee to work comfortably without needing to over-reach, sit or stand too long, or use awkward postures (correct ergonomic design).

According to the Ergonomics Center of North Carolina, “Seating is a primary focus of every office environment. It is the first and most essential workstation element that should fit the needs of the user and the tasks at hand. In an ideal world, once the chair meets these needs, the rest of the workstation can be positioned relative to the employee in the chair.”

Therefore, correct chair design is a critical component in every ergonomic office setting. Proper chair design, the Ergonomics Center says, should encompass the following attributes: adequate support, task effi- ciency, posture adjustability, and comfort. Conversely, poor chair design may result in decreased productivity, disgruntled employees, pain and discomfort, and even musculoskeletal disorders.

An essential element crucial to chair design is the seat pan. The primary job of the seat pan is to provide adequate support for the buttocks and thighs. The sitting bones, or bony protrusions in the buttocks known as the ischial bone tuberosities, are the focal points of pressure due to the weight of the body while seated in a properly adjusted (for height and tilt) seat pan. The tissues surrounding these bones are exposed to extremely high pressures and are the sources of discomfort for seated workers.

Research has also concluded that uniformly distributed body weight over the buttocks region and minimal weight under the thighs results in increased comfort and worker efficiency.

A worker productivity study, conducted by the Internal Revenue Service, confirmed what ergonomic experts and physical therapists have been saying for years: That as the day progresses, worker productivity decreases significantly, and ergonomic seating can have a measurable impact on improving worker productivity.

The study found that whatever a worker’s measured output, it is at its peak at the beginning of the day (allowing for a certain amount of “getting started” momentum), when the employee has the most energy, etc.

As the day wears on, his or her productivity declines until they leave worn out at the end of the day. Ergonomic equipment enhances productivity by slowing that decline in productivity, which gives you an average increase in output throughout the day. Increased output usually translates to increased dollars, and the payback on the ergonomic equipment can be figured accordingly.

As a means of proving [to the IRS] that a properly designed and adjusted ergonomic chair could make a substantial difference in worker productivity, a test was initiated by the Industrial Engineering Staff at the Internal Revenue Service’s Austin Service Center. The operator in each case was a data entry operator on permanent staff, well-experienced in his/her job function.

Production histories for each employee were available, measured in terms of documents per hour. In two separate studies, only the chair was replaced in two distinct units, with all other production criteria remaining consistent.

The test was to determine the chair’s contribution to production for a particular test week (40-hour week). Performance during the test week was compared to the average production from prior weeks.

The study results showed a productivity increase of 8 percent.

QWhile a portion of this improvement in production was possibly due to some increase in the production rate, each operator expressed the opinion that a good portion of the increase was due to the operator being more comfortable [in their seated posture], thereby being able to produce for longer periods without the need to move around, take a break, etc.

Comfort and ease of adjustment to fit different anatomies were important contributions to increased production. Although an 8 percent improvement in overall productivity is significant considering the number of employees that accomplish data entry, the actual increase may be higher yet. In this career field, 5.21 percent of total direct hours are used as sick leave. Of that total, approximately 40 percent of sick leave is attributable to neck, shoulder and back discomfort.

The IRS said it expected sick leave for this type of ailment to be reduced during the next year due to its purchase of ergonomic chairs with posture control.