A question I often find myself asking individuals is … ‘Do you like having arm rests on your office chair?’
I would say that 95% of the time, the answer is … ‘Oh, I don’t know, I’ve never really thought about it. But now I do, I guess I rarely use them, and I often find they get in the way’.
The more we talk about the arm rests (or handles as I hear many people refer to them), the more I find individuals remind themselves of times where they couldn’t get close to the desk because of their chairs arm rests, or where they have had to lower them so far that they were never in use, or they couldn’t tuck the chair under their table at the end of the working day which resulted in an obstruction and frustration (and so on and so on with other negative thoughts) that they end up answering my original question with … ‘No, I don’t like arm rests’.
An example of fixed arm rests.
Our arms are surprisingly heavy … Some research suggests that one arm can weigh between 4 and 6% of your total body weight.
Why do I ask this question?
I want to understand the barriers that user’s have found with arm rests, because believe it or not, our arms are surprisingly heavy, and the provision of suitable arm rests can help to reduce tension that this weight can otherwise impose.
Some research suggests that one arm can weigh between 4 and 6% of your total body weight. So for someone that weighs 70kg, that could be as much as 4kg - the equivalent of roughly 10 cans of baked beans - per arm! That is a lot of weight for the neck and shoulders to bear over the course of a working day, especially if your desk set up is not optimal and encourages poor upper limb postures that increases static loading and the onset of muscle fatigue.
Why could your arms adopt awkward postures?
Input devices (keyboard and mouse) being positioned too far away.
Repetitive overreach for other items such as paperwork or phone (or that important glass of water).
Chair height set too low, with the sitting elbow height lower than the working surface, encouraging shoulder elevation or elbow extension.
Or indeed, chair height set too high, encouraging extension at the elbows (ultimately leading to forward postures).
Arm rests set too high, shrugging the shoulders upwards and leading to adaptive changes to the shoulder muscles and tendons.
Arm rests far longer than your ‘abdominal thickness’ - odd term, but essentially an arm rest should not be any longer than you are from your spine to your belly button. If the arm rests are too long, they will prevent you from sitting close to your equipment.
How could these issues be addressed?
The first few points are often very easy to address with education on a suitable set up, such as encouraging close placement of the keyboard and mouse or adjusting the chair height so your elbows are level with the working surface. However, the last few points are often difficult to address, especially when the arm rests are fixed, which sadly is the case with so many lower cost chairs! It is also usually these fixed arm rests that user’s have experience on, which fuels the negative thoughts towards them.
By having ‘fully adjustable’ arm rests on a chair, you are more likely to ensure suitable upper limb support, acting as an extension of your desk surface, helping to hold those 10 cans of baked beans.
What should you look for in good quality arm rests:
Height, width and depth adjustability - this can help to position the arm rests just below your elbows for optimal support.
Rear positioning - a lot of arm rests are fixed to the centre of the seat pad, so when you adjust the seat depth to account for your thigh length, the arm rests move with this which often impacts close positioning to the desk. Arm rests that are fixed to the rear structure of the seat mean that they are not affected by other changes.
Attachment to the base or seat of the chair, not the back rest - those arm rests that attach to the back rest mean that the angle of them will change as the angle of the back rest changes. This could result in the arm rests adopting an incline and no longer being parallel to the surface of the desk, which may not be comfortable.
It is also very helpful to check the the range of adjustability on arm rests in comparison to your body measurements:
the arm rest height should be equivalent to your sitting elbow height
the arm pad length should be equivalent to your abdominal thickness
the arm rest width should be equivalent to your elbow to elbow width
So… are arm rests helpful?
YES! My personal opinion is that arm rests are by no means fundamental, but they certainly can be helpful.
However, as with all things ergonomic, they need to be right for you, otherwise they can be a hinderance. You are more likely going to get them right when they are fully adjustable, so you can overcome those barriers you may have previously experienced.
If you are experiencing upper limb discomfort whilst working at your computer, please do get in touch. A workstation assessment can help to address those discomforts and make recommendations to help you work more comfortably!
