Chairs are probably the most popular topic that we hear about in ergonomics and for good reason! Have you ever sat in a chair and just knew that something wasn’t right? Or are you in the market to purchase a new chair? The whole process with chairs can seem quite daunting at times – there is a lot of information to consider and a lot of chair options out there! So, we hope to provide you some value to clarify some of the BIGGEST myths (in our opinions) that we see about chairs.
MYTH #1: The most optimal position of the backrest is 90 degrees
This is probably the BIGGEST myth that I come across. Whenever I see media or infographics related to ergonomics, it’s usually of the user sitting with their backrest positioned absolutely vertically, or 90 degrees. Research has now proven that those stereotypical office ergonomics graphics of the person sitting 90 degrees is actually not the most neutral back posture to sit in. Now. I realize that it’s not as bad as leaning forward, but it is certainly not the most ergonomic posture either. I think that it would be safe to say that this is the marketing of ergonomics that is not entirely based on research. Let’s go back to what the research does say. It says that a slightly reclined seating posture actually reduces some strain on the lower back. By sitting slightly reclined (between 95 and 115 degrees), the weight of the back is shifted to the backrest instead of the lower back region. This may improve comfort for some users.
As cliche as it sounds, the best back posture is truly the next posture when it comes to maintaining the health of your back. By slightly shifting how the back support is positioned (within the 95 and 115 degree range), it can be valuable as these iterations limit long-term wear and tear on our spine. PRO-TIP: Taking a break from sitting is probably the biggest value-add in pro-health behaviours.
Now, we know that the sitting posture with the most risk for the back is leaning forward. Why is it so risky? Unsupportive back postures place a lot of strain on the lower back region because leaning forward in a chair creates a torquing effect. Unsupported back postures have been linked to discomfort.
MYTH #2: Armrests are always necessary
Let’s add some context to this Myth. Under ideal circumstances (appropriate height and width adjustability) it is definitely recommended to use armrests. There has been a considerable amount of research that has identified positive findings for armrests; they reduce shoulder and upper back strain related to statically holding the upper extremities.
Like we said, armrests can be tremendously useful under optimal conditions. Why? Let’s look at the facts. A neutral shoulder posture is the best position possible to keep the shoulder relaxed; the shoulders are not raised or depressed, nor is the upper arm flexed away (called abduction) from the user’s torso. Instead, the upper arm is comfortably tucked next to the user’s torso when they are working. Theoretically this working posture will not expose the user to any ergonomic risk in developing a musculoskeletal injury, nor will it contribute to any pain or discomfort related to a past injury.
If an armrest forces the user to abduct, raise, or depress their shoulder, then the armrests are exposing the user to the risk of shoulder or upper back discomfort. The primary solutions should be to adjust their existing armrests or retrofit adjustable armrests to the chair. If no other solutions are viable, and the user is already experiencing shoulder discomfort, it may be in their best interest to lower (so they are no longer in use) or remove their armrests. I know that this is a controversial idea for some but if the armrests are not optimal for the user, then they are exposing that person to ergonomic risk. Not surprisingly, non-optimal armrests are a very common occurrence in the office.
MYTH #3: One chair does not fit all
Comfort is a subjective term. One person may think that a chair is the absolute best, while at the same time, for the same chair someone else may find it to be extremely uncomfortable. In my experience, most offices have only one type of chair available for staff. The interesting thing about chair design is that very rarely does one type of chair fit the majority of the working population. This presents a challenge for those people who are not considered to be ‘average’. And because of this, the ‘one size fits all’ chair design usually misses a large portion of the population.
Here are some tips when looking at bringing in new chairs:
- Offer more than one chair to staff. I have found that offering 3 different types of chairs (or sizes) to staff can be incredible valuable.
- Ensure that the ‘sample’ chairs are all the same colour. Black is usually best to avoid any user biases.
- Allow staff to try chairs. Research has shown that the minimum amount of time should be about 20 minutes for them to determine comfort. Ideally, have staff try chairs in their workstations. For instance, when I had my own Ergonomics Showroom, staff would sign-out a sample chair for 2 weeks. This strategy received a lot of positive feedback from staff.
MYTH #4: A good chair is expensive
Not all good chairs are expensive! The truth is that the deciding factor in chair design is its functionality and comfort. PRO-TIP: Before jumping in and purchasing a brand new chair, take another look at your chair. I see a lot of people working in chairs who think that they need a new chair, but really they just need to have their chair adjusted! Check out our Ultimate Chair Adjustment Guide for some valuable insights on practical chair adjustments.
Here are some following features that should be considered when you are looking for a chair:
- Lumbar (lower back) support (adjustable whenever possible)
- Backrest height adjustability
- Multi-tilt, (ability to angle and lock the backrest)
- Synchro-tilt functionality (ability to change the angle of the seat pan)
- Chair tension adjustability
- Seat height adjustability
- Seat pan depth adjustability (request slider)
- 5-prong base with appropriate castors (wheels) for floor type
- Option: Armrests, (ensure height, width adjustability), Headrest
There you have it, our post on the Top 4 Myths about chairs. If you need more support, no problem. Leave a comment below!