Yesterday I was keenly reminded of two different opinions when it comes to the use of armrests on a chair: those who insist that armrests must be attached on a chair and those who think that the best possible posture is attained with no armrests attached to the chair. I’m sure that you have heard of this debate before.
Where do you stand (or sit!) in the matter?
There are some people that cannot go without the use of an armrest. There has also been a considerable amount of research that has identified some key attributes for the positive use of armrests on chairs. Armrests reduce the shoulder and upper back strain related to holding the upper extremities up.
The thing is that armrests are really only useful under optimal conditions. What this means is to enhance the ergonomics of a set-up, a neutral shoulder and elbow posture must be met.
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 an ergonomic injury, nor will it contribute to any pain or discomfort related to a past injury.
In addition to the postural benefits, armrests can be incredibly useful in helping some workers get into and out of their chairs. This can be overlooked by many, and only truly realized when the armrests are absent.
Ergonomic risk occurs when optimal armrest positioning cannot be obtained. Most offices have only one type of chair available for staff. The interesting thing about chair design is that very rarely does one chair fit the majority of the working population. This presents a challenge for those people who are not considered to be ‘average’. The ‘one size fits all’ chair design usually misses a large portion of the population in the following ways:
- For smaller or more petite staff, there can be a substantial mismatch between the armrest placement and shoulder width. Simply put, armrests are too wide for the person. When the armrests are too wide, this results in outwardly flexed (abducted) shoulder positions. This is considered to be an awkward posture and can result or contribute to discomfort overtime.
- Additionally the armrest height adjustability may lack accuracy so it results in awkward shoulder positions of either the shoulders being raised up or depressed. This may also be the reason that the person is complaining of discomfort.
Further to the above risks, the armrest length may be too long and can prevent the user from getting as close as possible to the workstation. This increases the user’s reach. This is considered to be a negative as it can contribute to shoulder awkwardness in addition the user leaning forward (which is a non-neutral back position).
Following this process there are two different streams in our quest to reduce shoulder discomfort and injury. The two different streams are:
- The user is working with optimally positioned armrests OR
- The user is not working with optimally positioned armrests AND is experiencing shoulder discomfort related to this.
I have done work with a past client who did not have optimally positioned armrests and was also complaining of shoulder pain. I also noted that the armrest length prevented my client from getting close to the workstation. We ruled out any outside causes to this pain, and concluded that it must be a result of the non-optimal placement of the armrests: they were too wide for my client and also lacked accurate height adjustability. Normally my client would say that she felt that she could only use one armrest at the time, just because they were far too wide for her.
There were three options that I suggested to my client. These options were either removing the armrests entirely, lowering them so that they were out of her use, or replacing them with armrests that are both height and width adjustable. After much thought on positives and negatives of each approach, we decided that replacing the armrests with a more adjustable armrest was the best option.
It was not as complex as my client originally thought to replace the armrests, she found an alternative armrest that met our metrics on her chair manufacturer’s website. After following up with my client several months after the assessment, she reported that the new armrests were incredibly useful and also really reduced her shoulder pain.
Note that the ideal armrest would have height, width, forward-to-backward slide, and inwards-outwards pivot, these options are all of the ‘bells and whistles’ that you would be able to have in an armrest.