I hunched over a laptop for three years straight and developed a knot between my shoulder blades that felt like someone had wedged a golf ball under my skin. I bought a posture corrector harness — the kind that pulls your shoulders back with elastic straps. It helped while I wore it. The moment I took it off, I rounded right back down.

The problem was not my muscles. It was my setup. Here is what actually changed things.

Start With Your Chair Height

Sit in your chair and let your arms hang naturally at your sides. Your elbows should be at a 90-degree angle when your hands are on the keyboard. If your elbows are below your hands, your chair is too low. If your shoulders are shrugged up toward your ears, it is too high.

Your feet should sit flat on the floor. If they do not reach — and mine did not when I got the chair height right — use a small box, a stack of books, or an actual footrest. Dangling feet pull your pelvis forward and round your lower back.

The Screen Height Fix

The top of your screen should be at eye level. Most people have their laptop or monitor too low, which tilts the head forward. Every inch your head shifts forward adds roughly 10 pounds of force on your neck and upper back.

I stacked two thick books under my monitor. It cost nothing and my neck stopped hurting within three days. If you use a laptop as your only screen, get a separate keyboard and raise the laptop. You cannot have good posture and use a laptop keyboard at the same time — the physics do not work.

The Two-Minute Reset

Set a timer. Every 45 minutes, do this:

• Roll your shoulders backward in slow circles, 5 times
• Tuck your chin straight back — like you are making a double chin — and hold for 5 seconds. Repeat 3 times
• Stand up, reach both arms overhead, and lean slightly backward

This takes less than two minutes and it resets the muscles that have been holding a static position. The chin tuck especially — it is the single most effective exercise for forward head posture and it looks so ridiculous that I only do it when nobody is around.

I do not have perfect posture. I still slump after lunch. But the golf ball between my shoulder blades is gone and I can turn my head to check my blind spot while driving without wincing.