The most important tool in the office is the chair. The chair should fit the user’s physical characteristics—stature, leg length, torso height, etc.—and accommodate all the elements of the user’s task and job. Think of a typical conference room chair. Most recline or lean back up to 45° from vertical as this is a comfortable position to be in when listening. How comfortable or attentive would we be if we had to sit in a folding chair for an all-day meeting? It’s the same way with the office chair. Different tasks require different postures and the chair should accommodate a full range of working postures throughout the day.
The minimum features that an office chair should have are:
This accommodates differences in overall stature, leg length, and torso height. Office chairs are available in three different height ranges:
- Standard—16 to 21 inches
- High—19 to 23 inches
- Low—14½ to 19 inches
Before purchasing chairs, research the demographics of your workforce and your geographic hiring area. If you find that most in your workforce are shorter in stature, then a standard chair at its lowest height of 16-inches is actually too high for a 5-foot female. It’s best to provide a chair whose lowest height is around 14½-inches but only if the work surface adjusts to accommodate the lower seated height.
For those in your workforce that are either very tall, very heavy, or both, a chair will be needed to accommodate them as well. Chairs typically are designed to support 250 to 270-lbs. There are chairs specifically built to meet the needs of larger, heavier people. Just changing a standard pneumatic lift to one that claims to be “heavy-duty” is not enough. In addition to the lift, the armrests, the base, and the backrest must also be designed, built, and attached to support the added stresses placed on them by a larger, heavier user.
If the seat pan is too deep and does not slide backward, then the backrest should be able to move forward to shorten the seat pan depth. If not, the user may sit perched on the front edge of the seat.
The backrest should adjust up and down allowing for the correct positioning of the low back or lumbar support. Low back or lumbar support is as critical in chair comfort as the arch support is to shoe comfort. If the lumber support is positioned correctly, it will take the weight of the upper body off the lumbar discs and transfer it to the backrest. Adjust the backrest up and down incrementally until it feels comfortable and supportive. If the backrest does not provide enough low back support, then adding a small lumbar pillow, a lumbar roll, or even a small rolled-up towel should be adequate.
Seat Pan Adjustability
Most seat pans are 17-inches deep. For users with very long legs, this is not deep enough to support the thighs with even pressure distribution and at least two inches of space between the back of the knee and the front edge of the seat. A smart decision would be to purchase the chair with a seat pan that slides forward and backward. This adjustment changes the seat pan depth from 17 up to 20 inches. This 3-inch difference in depth is huge for someone with long legs. Just this one adjustment will accommodate up to 95% of any workforce.
Seat Pan Tilt
The tilt feature allows the user to incline the seat pan a few degrees for more forward work, such as writing. Even a few degrees of tilt helps reduce back flexion (leaning forward) during forward work.
Fixed armrests rarely fit the user. They tend to be too high, too low, or too wide. Adjustable armrests are best especially if they go up and down, in and out, and rotate to follow the angle of the forearm. Armrests should be wide enough to easily get into and out of the chair. If the armrests do not fit, then consider removing them.
A chair is best when it can move with the user. This movement occurs by adjusting the tension so that the backrest floats freely, with or without a locking mechanism. The degree of tension is a personal preference.
Five-Star Base and Wheels
Every office chair on the market today has a 5-star base for stability. The most mismatched item of a chair is the wheel to the floor surface.
A wheel is a component of a caster. The caster is attached directly to the chair leg on a plate or stem. The size of the wheel is standard for most office chairs. Also standard are harder wheels, which are good for carpeted surfaces. Because the carpet poses resistance, the wheel must be hard for less friction. For hard surfaces, such as hardwood, linoleum, tile, or even plastic mats called “carpet protectors,” a softer wheel is best. Since a hard floor surface is slick, the softer wheel provides more friction. It is not uncommon to put a mat under an office chair with hard wheels only to discover that when the user stood up, the chair rolled away. Then, when they tried to sit back down, the chair was not underneath them and they fell.
Levers should be operable from a seated position, be long enough to reach and activate, and have simple diagrams such as arrows showing the direction of movement. Just because a chair may have six or more levers and knobs does not make it a good chair. In fact, the more controls the chair has the more errors in operation and the more time it takes to adjust.
Because the population is growing in size, those who are either very tall and/or very heavy should be given a chair with a higher weight capacity than the standard 250 to 270-lbs. Larger people get into and out of a chair differently. They tend to push horizontally on the armrests as they get up. If the decision is made to provide chairs with a higher weight capacity for larger people, make sure that it is rated as such by the Business and Institutional Furniture Manufacturers Association (BIFMA) and that the manufacturer is a major manufacturer of office furniture. When considering chairs to accommodate larger users, choose one that looks similar in style and fabric to the rest of the chairs within the organization. No one wants to be singled out as special needs so accommodate with dignity.
When researching chairs, consider these points:
- Does your business have multiple shifts/multiple users?
- What is the expected return-on-investment? It is not unreasonable to expect that a $400.00 chair could result in five minutes of increased productivity a day. This increase in productivity means that the chair could be paid for in less than 18 months.
When selecting either one chair or a hundred chairs, it’s best to understand the warranty.
- How long is the warranty?
- What does it cover?
- How will the vendor handle repair(s)?
- Is there an on-site repair service?
- Is there an internal system for reporting damaged or broken chairs?
- Are there enough replacement chairs so that if one is being repaired, will the user have a similar chair to use?
- If a broken chair is pulled for repair, is it tagged as such so that it is not mistakenly put back into service before the repairs were made?
- What maintenance should be done to the chair and how frequently?
Lastly, never assume that once users receive their new chair, they will adjust it to fit them. Vendors should be available to train the user(s) on all the adjustments and may even be able to fit the chair to the user(s). If a large number of chairs are purchased, delegate a trainer or trainers to be trained by the vendor. They then become the dedicated trainer(s) for the rest of the facility. If small groups of users are being trained, have them bring their chairs to the training to follow along with the adjustment sequence. Also, many chair manufacturers now provide online videos which demonstrate how to adjust the chairs they supply.
The above evaluations and/or recommendations are for general guidance only and should not be relied upon for legal compliance purposes. They are based solely on the information provided to us and relate only to those conditions specifically discussed. We do not make any warranty, expressed or implied, that your workplace is safe or healthful or that it complies with all laws, regulations or standards.