My Neck Was Killing Me Every Afternoon for Six Months. Then My Mac Figured Out Why.

What the Camera Found in 40 Minutes

The first session, I got a posture alert 38 minutes in. Forward head position. Second session: flagged at 41 minutes. Third session, I caught myself leaning in before the alert fired and actually sat back. The neck tightness that afternoon was noticeably better.

Turns out I wasn’t just “sitting at a computer.” I was gradually sliding into a C-shape over the course of each morning, without ever noticing it, until my head was several inches forward of where it should be. By 2pm the muscle strain had accumulated enough to be uncomfortable. This had been happening every day for months.

The Reason Posture Advice Never Sticks

The frustrating thing about bad posture is that it’s completely invisible while it’s happening. You don’t feel yourself slouching in real time. You feel the result — later, when you stand up and your back aches, or when you get that afternoon neck tightness you’ve been attributing to something else.

I’ve tried the usual fixes. Ergonomic chair. Monitor at eye level. Sticky notes on the screen that say “SIT UP” (genuinely did this). The problem is there’s no feedback loop. I’d think about my posture for a few days after reading an article, drift back to the forward lean within a week, repeat. Your body adapts to bad positions. A posture you’ve held for twenty minutes feels neutral. Your brain registers it as normal and stops flagging it.

What actually breaks that loop is an external signal that fires consistently every time the behavior happens, without requiring you to remember to check.

How Camera-Based Posture Detection Works

The core idea is straightforward: your Mac’s front camera can see your face and shoulders. Computer vision can estimate where your head is relative to your torso and whether you’re tilting or craning forward. Do that continuously in the background and you have a real-time posture monitor that doesn’t depend on you remembering to use it.

TypeMetrics’ posture coach runs as part of the app on Mac. The processing stays local — nothing is uploaded, no video is stored. On my M2 MacBook Air I haven’t noticed a performance impact from leaving it active. It doesn’t keep the camera indicator light on continuously either; it samples periodically rather than streaming the whole session.

When it detects that you’ve crossed your posture threshold, you get a subtle notification. Not a jarring alarm — just a gentle nudge. You adjust, it stops. That cycle, repeated consistently over a few weeks, is what actually builds a habit. Not the initial intention. The repeated feedback.

Three Months of Tracking: What Changed

After roughly three months of using the posture coach most workdays, here’s what I’ve actually noticed:

• Alerts got less frequent. In week one, I was getting flagged roughly every 45 minutes. Now it’s once every 2–3 hours, and sometimes not at all during short sessions. I haven’t been consciously trying to sit better; I’ve just started noticing the early signs of a forward lean before it gets bad enough to trigger an alert.
• The 2pm neck tightness is mostly gone. Not entirely — long high-stress days still catch up with me. But the baseline shifted. Afternoons feel different from how they did six months ago, and I’m not doing anything special during them.
• Alerts started acting as break prompts. When I get a posture nudge, I tend to pause for 30 seconds rather than just correcting and plowing on. That unplanned rest probably helps my focus and my eyes too, though I can’t isolate that effect cleanly.

The Typing Angle: Why It’s the Same App

TypeMetrics is primarily a typing speed and accuracy tracker — that’s what the name is about. It measures your WPM in real-time during actual work (not a typing test, your real typing), shows keyboard heatmaps so you can see which keys you hesitate on, and includes 80 structured bilingual lessons in English and French for actually improving your speed.

What’s interesting is that posture and typing performance are more connected than I expected. Watching my WPM in real-time, I noticed it drops noticeably when I’m tired or distracted — and also when I’m hunched over the keyboard. There’s a visible correlation between forward head position and slower, more error-prone typing. Having both metrics in the same app makes that relationship obvious in a way I wouldn’t have found otherwise. The heatmaps also revealed I was heavily dependent on visual feedback for right-side keys (bracket, quote, backslash) — something the coding-specific lessons have been steadily fixing.

How to Actually Start

TypeMetrics is a free download on the Mac App Store (it’s also on iOS, which has the lessons and WPM tracking — but the camera posture coach is Mac-only). Download it, go to Settings, enable the posture camera, give it access, and choose your alert threshold. Start with “moderate” rather than “strict” — strict fired on me almost constantly in the first two days, which was annoying enough that I nearly turned it off. Moderate lets you get used to the feedback rhythm before tightening the threshold if you want to.

Day one you’ll probably be surprised how often it goes off. Week two, less so. Month three, noticeably less. That downward trend is the whole point — the goal isn’t to live with constant alerts, it’s to make the alerts less and less necessary. That trajectory is the only posture advice that’s actually worked for me after years of trying the others.