Quick Answer: Armrests set too low give you no forearm support, so your shoulders carry the weight of your arms all day — commonly a cause of upper trapezius fatigue and neck tension. Tall workers have longer arms and usually sit higher, which makes standard armrests proportionally lower still. Set them so your shoulders are relaxed and your forearms rest level with the desk, and adjust them before you touch anything else.

You raised the chair. You found the lumbar knob. You bought a monitor stand.

And your shoulders and neck are still tight by three in the afternoon.

Check what your arms have been resting on. There is a fair chance the answer is nothing.

Why do unsupported arms cause neck and shoulder tension?

Because your arms are heavier than people assume, and something has to hold them up.

Each arm accounts for roughly five percent of body weight. For a 75kg person that is about 3.7kg per arm, held out in front of you for most of the working day. If your forearms are not supported by an armrest or the desk, that weight is suspended from your upper trapezius and levator scapulae — the muscles running from your neck to your shoulders.

Those muscles are perfectly capable of holding that load. What they are poor at is holding it continuously for hours without a break, which is exactly what a desk job asks of them.

The symptom pattern is familiar to a great many desk workers: fine in the morning, tightening through the afternoon, worse on busy days, better on days away from the desk. That pattern is characteristic of sustained low-level load rather than injury.

Why is this worse for taller workers?

Two reasons that stack.

You sit higher. A taller worker sets the seat higher to get the hips above the knees. Most armrests move with the seat, but their adjustment range is designed around average seat heights, so at the top of your seat range the armrests are frequently still short of where your elbows are.

Your arms are longer. A longer humerus means the elbow sits lower relative to the shoulder when the arm hangs, and a longer forearm means more mass further from the joint. Both increase the demand on the supporting muscles.

There is also a desk problem underneath it. Standard desks are commonly 72 to 75cm high, which is low for a tall worker. If you are also using a non-adjustable desk, you may be dropping your seat to reach the desk comfortably, which puts your knees high and your armrests low simultaneously — the worst combination available.

How should you actually set them?

Work from the elbow, and set the desk relationship first.

Step one: sit properly. Feet flat, hips slightly above knees, back supported. Use a footrest if the seat has to be high for the desk.

Step two: let your arms hang. Completely relaxed, shoulders down. Now bend your elbows to about 90 degrees.

Step three: raise the armrests to meet your forearms. Not to lift your shoulders — to meet your arms where they already are. If raising the armrest raises your shoulder, it is too high. If your shoulder drops when you take your arms off, it was doing work it should not have been.

Step four: check the width. Armrests set too wide make you abduct your arms, which reintroduces shoulder load. They should sit close to your body, roughly under your natural elbow position.

Step five: check against the desk. Ideally armrest height matches desk height so your forearm can move between the two without a step. If the armrests are higher than the desk and hit it, either lower the armrests slightly or raise the desk.

If your armrests do not reach high enough at full extension, the practical fixes are raising the desk on risers, using a keyboard tray, or replacing the chair. Foam armrest pads add a couple of centimetres and cost very little.

Myth vs Fact: Office Chair Adjustment

Myth: Armrests get in the way and are best removed. Fact: They get in the way when they are set wrong — too high, too wide, or colliding with the desk. Correctly set, they remove a sustained load from your neck.

Myth: A standing desk solves everything. Fact: Standing solves some problems and creates others. The evidence favours alternating rather than replacing. And a standing desk set at the wrong height reproduces the same shoulder problem in a different posture.

Myth: An expensive chair is automatically better for a tall person. Fact: Price correlates with adjustment quality, not with range. Check the actual maximum seat height and armrest height in the specification. Some premium chairs have a narrower range than cheaper ones with a taller gas lift.

Myth: Good posture means sitting up straight and holding it. Fact: The best posture is the next one. Movement matters more than any single position, and a chair that supports you in several positions beats one that enforces a single perfect one.

Myth: If nothing hurts, the setup is fine. Fact: Cumulative load is quiet until it is not. Setting the chair correctly costs five minutes once, which is a reasonable insurance premium.

FAQ: Tall Desk Setup Questions, Answered

What if my desk is too low and cannot be adjusted?

Desk risers are inexpensive and effective, and even sturdy blocks under the legs work. Raising the desk is almost always better than lowering yourself, because it fixes armrest height, knee angle and monitor height together.

How high should my monitor be?

The top of the screen at or slightly below eye level, at roughly arm’s length. For tall workers this usually means the monitor needs to be higher than a standard stand allows — a riser or a monitor arm with a long column is worth the small cost.

Does any of this help existing neck pain?

It can help reduce ongoing load, but this is general information rather than medical advice. Persistent or worsening neck pain, especially with any arm symptoms, should be assessed by a qualified professional.

TL;DR:

• Each arm is around five percent of your body weight, and unsupported arms load your neck and shoulders all day.
• Tall workers sit higher with longer arms, so standard armrests are proportionally lower still.
• Set them to meet your relaxed forearms at 90 degrees, close to your body, level with the desk.
• If the range is not enough, raise the desk rather than lowering yourself — it fixes several problems at once.

It is the one adjustment on the chair that almost nobody makes, and for a tall desk worker it is usually the one that matters most.