Evidence · 2 min read
Tech neck: the 60° myth and the real numbers
Hansraj 2014, modelled vs measured.
The headline number
A 2014 paper by neurosurgeon Kenneth Hansraj modelled the load the cervical spine carries as the head tilts forward. At 0° (head balanced on top of the spine) the load is about 5 kg — your head’s weight. At 15°, roughly 12 kg. At 30°, 18 kg. At 45°, 22 kg. At 60° — about the angle of looking down at a phone in your lap — roughly 27 kg. The “60 lb” figure that went viral is the same number in pounds.
What the paper actually says
It is a mathematical model, not an in-vivo measurement. The exact numbers depend on the assumptions Hansraj fed in. Cadaver studies and EMG work in adjacent literature produce figures in a similar ballpark, so the shape of the curve — load climbing steeply as the head tilts forward — is supported, even if the absolute numbers carry uncertainty.
Why duration matters more than peak angle
A 60° glance that lasts five seconds is a glance. A 30° “pretty-good” angle held for 40 minutes is a load history your tissues remember. The read on the creep phenomenon gets into why.
How Plumb uses this
Camera mode reads head tilt from the TrueDepth camera; hands-free mode reads it from the motion sensors in your AirPods. Either way, sustained drift past your calibrated neutral is what triggers a nudge. The goal isn’t “0° forever” — it’s “noticed before duration accumulates”.
Plumb is a wellness and posture-awareness tool, not a medical device. It doesn’t diagnose, treat, or monitor any condition. If anything about your body concerns you, see a qualified clinician.
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