The Ergonomics Of Armrests

Let’s start this post with a Fun Fact. Computer based customer service work aka call centre work is one of the most rapidly growing occupations in the world according to this research. Maybe it’s a bit obvious… but research now supports it! It’s no surprise that upper body discomfort in the arms and neck are common and on the rise too. So what do we do? Well one solution that has been proposed is it to use arm supports aka armrests. If you are new to the ergonomics community, nothing divides us like whether or not armrests should be used in the office.  

So the Question is: Do you use armrests? The answer is quite dividing. The debate can even get heated. There are those who insist that armrests must always be attached. But at the same time there are others who say that the best possible posture can only be attained with no armrests attached to the chair. In this post I’m going to share insights about both arguments as well as some of the reasoning behind it.   

The Ergonomics Of Armrests

It depends on a few things to whether or not armrests are the best ergonomic solution for a particular person. An optimal ergonomic set-up is when armrests can be fully adjusted (adequate height, width, and length) to fit the user like a glove. No awkward postures, no discomfort. Everything is perfect. 

Ergonomic risk occurs when armrests can’t be fully adjusted to fit the user like a glove. Remember ergonomics is here to adjust the work environment to fit the person, not the other way around. Keep this in mind when thinking about armrests.

For reference: Optimally placed armrests should slide just underneath a neutral elbow position so that the shoulders stay in a neutral (aka comfortable) posture. An armrest essentially carries the weight of the arm so that the shoulders can ‘rest’. A neutral shoulder posture is the best position possible to keep the shoulders 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 their torso when they are working. Theoretically this working posture will not expose the user to any ergonomic risk in developing discomfort or injury, nor will it contribute to any pain or discomfort related to a past injury.

To work in a neutral position, the arms and shoulders should be in a resting position. In the majority of cases (like 99.9%) this means that the arms are resting along the person’s torso – the elbow is pretty much directly under the shoulder. 

If this is in place (super-adjustability in height, length, and width), arm supports can be somewhat beneficial at reducing arm injury or discomfort. This fact is supported by the systematic review completed by the Institute for Work and Health in Toronto a couple of years ago. Their researchers found moderate evidence of an optimally adjusted arm support with the reduction of an arm injury. This could be because optimally set-up armrests can reduce muscle loading for the upper extremity as well as for the spine.

But here’s the thing. Armrests that cannot be adequately adjusted for the user is a major red flag. For petite users who use a ‘regular chair’, the armrests can be too long so they can’t get close enough to their desk to work. This can result in more of a reach (and more arm/back ergonomic risks) to the keyboard and mouse. This may seem minimal, but it’s a constant work and awkward position that overtime can lead to arm/upper back discomfort and even injury! For many women (and even some men) most ‘off-the-shelf’ aka typical ‘one-size-fits-all’ armrests are simply far too wide for the them. This means that the position of the armrests are wider than their shoulder breadth so to use the armrests the user would need to move their elbow away from their torso (resulting in shoulder abduction aka an awkward posture). And, of course this is considered to be an ergonomic risk for the shoulder and upper back. Just like the reaching example, this may also seem like a trivial ergonomic risk. But over time of constantly having the elbows away from the torso can result in a lot of shoulder and upper back discomfort and even injury.

In the end it boils down to if the amount of adjustability of the armrest is compatible to the person using it. 

Here’s what the research says.

Keep in mind that all of these findings are for optimally positioned armrests. This means that the person using them is an optimal working position and neutral posture. They have no pain whatsoever and the workstation fits them like a glove. For optimally placed armrests the research has found that:

  • This study found that forearm support reduces shoulder and elbow loads and a moderate level of evidence suggests that forearm supports can reduce the risk of developing neck and back injuries. This is big news for those who are on the fence about using armrests.  
  • Muscle activity decreased in the arms and upper back when subjects used arm supports while working, as found in this research. This is a good thing as it means that the muscles are more relaxed and optimally positioned. Being more relaxed/optimal generally means that there is a lot less susceptibility for an injury to occur.   
  • This study found that providing a large forearm support (like this –morency rests or you can also search ‘universal forearm supports’) combined with ergonomic training is an effective intervention to prevent upper body musculoskeletal discomfort/injury and reduce upper body pain associated with computer work among call centre employees. Here’s a cautionary warning: the researchers found if the morency support was less than 7.5 cm (3″) there was an increased risk of hand/arm discomfort. These researchers used a 30.5 cm (12″) padded arm support, aimed at providing support at the centre of the forearms. So if you are considering this as a solution, make sure that you look for the forearm support portion of a morency support being a fair distance – 12″ is the gold standard.

  • Here’s another interesting way to think of forearm support in the office. This study looked at a lot of different types of support (see the graphic below) and assessed muscle activity. Generally speaking, reported discomfort scores were lower for any support conditions compared to the ‘no support condition’ and when no support is provided, subjects appeared to use the mouse and the mouse pad as a support (a lot of ergonomic risks are associated with this behaviour). Those are things to keep in mind, especially in the context of whether or not the support that you have in your office (aka armrest or morency rest) is positioned optimally. If they are not, discomfort can easily be amplified and you might be dealing with a lot of ergonomic risks for discomfort or even injury. The optimally supported conditions (like the graphic shows below) compared to the ‘no optimal support conditions’ had less extreme wrist posture, shoulder muscle activity (aka less ergonomically risky) which is a good thing to improve comfort in the office. And, the researchers found that optimal forearm support provide a ‘mechanical ground’ to reduce the load from the weight of an extended arm on the shoulder muscles – another very positive finding of using arm supports.

  • It seems so straight forward, right? However the same research has found that there can be more ergonomic risk on the wrist if palm and forearm supports are used. What this all means is that you have to ensure that the workstation is set up for optimal positions every time and that the person using that workstation is very comfortable.  

Other Considerations with Armrests. Armrests can be useful in helping some workers get into and out of their chairs. This is especially true for the aging workforce and those with any physical disability.

Case Study

Let me walk you through a past ergonomic assessment. A past client of mine didn’t 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 of the shoulder pain (ie: no outside work activities could have contributed to it) and concluded that it must be a result of the non-optimal placement of the armrests: they were far too wide for my client but also couldn’t accurately adjust to what her optimal neutral elbow height was. Additionally, my client reported that she felt that she could only use one armrest at the time because they were far too wide for her (she was quite petite).

There were 3 options that I suggested:

  1. Remove the armrests entirely
  2. Lower them so that they were much lower than her neutral elbow height so she physically couldn’t use them, but they could still be used to help her in and out of the chair 
  3. Replace them with armrests that are both height and width adjustable

After much thought on positives and negatives of each option, she 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, we 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.

So to reiterate, the ideal armrest would have:

  • Height adjustability
  • Width adjustability
  • Forward-to-backward slide (sometimes called telescoping)

But whatever you choose to do the key element in any ergonomic set-up is that everything has to be set-up to fit the user like a glove. No awkward postures. Everything is in a neutral position and the worker is comfortable.

One Last Thing… 

I’d like to end this post with a question for you. Should armrests be used in the office? I would love to hear what you say in the comments below! 

If you liked this post, please share! It helps to get the word out!!  

Thanks so much to Sandi D who inspired this post! 🙂

 

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Through the administration of countless assessments in both private and public sectors, Darcie has gained a wealth of knowledge and built a successful practice in the field of ergonomics. She has extensive expertise in conducting office ergonomics assessments in large scale workplaces for all different types of scenarios, from simple adjustments to incredibly complex cases. Darcie also has vast experience in delivering training presentations on the various aspects of ergonomics “best practices” in the workplace. Darcie is a Certified Professional Ergonomist through the Board of Certification in Professional Ergonomics, as recognized by the International Ergonomics Association. She also has a Masters of Science, specializing in ergonomics. A little known fact about Darcie is that she once scored from half, off a free kick, in a university varsity soccer (football) match!

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