Your arms weigh about 10% of your total body weight, so if we can support them on an armrest, that’s a job your back won’t have to do.
You can see in the picture how only the women’s elbows are resting on the arm rest. This supports the upper arm and shoulder so that effort is not transferred to the thoracic and cervical area of the spine. At the same time, the wrists are resting in front of her completing the support. You can see also that the armrest pad isn’t too large, so her forearms are free to move and work, and she is able to get the chair close enough to the desk to work in a supported, relaxed position.
It should be pointed out that some jobs, tasks and some different types of seating might be better off without armrests, but we’re assuming here that we’re doing mostly desk based typing work, sat on a ‘typical’ office chair and desk.
It won’t matter how good the armrest is, it needs to be adjusted correctly to function properly. Note in the sample picture how the armrest tops are the same height as the desktop. As good as they are, if they were too low, then the user would be reaching up to the desktop and her elbows wouldn’t be on the armrest. The correct adjustment includes the complete workstation. It could be that the armrests are perfectly adjusted, but if the chair is too low, the user is still going to be reaching up with her hands to get to the keyboard.
There are many different adjustments available for an armrest, and some chairs will offer options on different armrests. At the very minimum, an armrest needs to be height adjustable. Other options you should consider include:
Width adjustment. Armrest can adjust for width in two ways. By adjusting the entire arm where it attaches to the chair, usually underneath. And sometimes the armrest pad on the top will slide in and out. Both have their advantages and disadvantages. Where the entire arm and top adjust from the bracket under the chair, we can increase width, but the minimum width will be dedicated by the width of the seat. If the user is too slim for the seat, we probably won’t be able to bring the armrest in enough. Where we have adjustment just on the top pad, there’ll be much less movement available, but where the chair is a good fit anyway, this should be adequate.
Fore and after adjustment. If we replace the slim lady in the picture with a much larger person, their arms and therefore the armrest are going to need to be further forward.
Foldaway arms hinge at the bottom so they can rotate down so they are completely out of the way.
Rotating tops spin on top of the arm. The reasons and benefits for this will vary from top to top. For some, it allows the rest to be angled towards the keyboard to remove some rotation from the wrist. For others with asymmetrical shapes the intention is for them to be swivelled through 180 degrees to achieve different lengths, instead of having a fore and aft slide designed in.
Trigger release can be a very important assessment consideration. Some users rely on the armrest for support when they sit and stand, and a sudden shift in the armrest top can be enough to cause a fall. For these users, ensure the armrest only moves when the user presses a trigger on the side to prevent this.
We’re also starting to see more armrests that hinge upwards to provide support when using a hand held device, such as a phone or a game controller.
More bespoke adaptations such as gel tops and brackets to adapt an armrest to help with specific issues are also available.
So if your choosing a new chair, be sure to ask what armrest options are suitable for you, and whether your chair is new or old, where you have an armrest, ensure it is correctly adjusted for you.