Ask a safety officer what a fall protection violation looks like and most will describe someone without a harness. On an industrial site, that is the rarer case. The far commoner case is someone wearing a harness, connected to something, in a configuration that has just removed most of the protection the harness was supposed to provide.
What actually happens in a low-anchorage fall
Fall arrest equipment is engineered around a specific geometry: the anchor point above the worker, the lanyard short, the free-fall distance small and the clearance beneath the worker sufficient for the system to deploy without them reaching the level below.
Attach the lanyard to a point at or below the feet and every one of those assumptions breaks at once. The free-fall distance becomes the length of the lanyard plus the distance to the anchor. The arrest forces rise, because the body is no longer falling into a decelerating lanyard but into a system reaching its limit. And the clearance required increases in the direction of whatever is below — a lower platform, a rack of pipework, a moving machine.
The change is not marginal. A configuration that was designed to arrest a fall of well under a metre can become a fall of several metres, with the anchor point below the worker and no way to arrest before impact.
Why it happens to competent people
Low anchorage is not primarily a knowledge problem. Ask the worker afterwards and they will usually tell you the anchor point was the wrong height. They knew. What they also knew was that the correct anchor was three metres along the steelwork, that reaching it meant unclipping and reclipping while exposed, that the task would take two minutes, and that the job had to be finished before the crane came back.
The behaviour is a rational response to an engineered situation: an anchor point installed for construction access rather than for the maintenance task that would follow, in a location where the task is short and the schedule is not.
Why supervision does not catch it
Because low anchorage is geometrically invisible from below. A supervisor at ground level sees a worker at height, a harness on the body, and a lanyard that appears to go generally upward. Whether the anchor point is above the shoulders or above the boots requires a viewing angle that ground level does not provide.
The behaviour also persists for seconds rather than minutes. A spot check samples a moment; the violation exists in the moments between two anchor points. The probability that a periodic observation coincides with the short window in which the configuration is wrong is low, and the probability that it is observed from an angle that reveals it is lower still.
What changes when the harness itself is measuring
A monitor on the harness measures orientation continuously rather than observing it occasionally, from the only position where the answer is unambiguous — the wearer. A posture sensor combined with on-device edge computing distinguishes high anchorage from level and low anchorage, and raises an alarm at the moment the configuration is wrong.
Two consequences follow. The worker receives a buzzer at the moment they clip in wrongly, which is the only point at which the correction is cheap. And the safety manager receives a record of how often it happened on that work front, which is the evidence needed to fund the anchor point that would have prevented it.
The permanent fix is an anchor point. A harness monitor does not replace engineered access — it identifies the locations where engineered access is missing, with data from real jobs. That is why the alarm record is as valuable as the alarm.