Do patients actually follow weight-bearing instructions?

The instruction, and the reality

“Non-weight-bearing for six weeks.” “Twenty kilos, no more.” These are among the most common instructions in orthopaedic surgery, and they are given in the reasonable belief that a patient who understands them will follow them. Three separate studies, using instrumented insoles or load sensors rather than self-report, found something different.

Strict non-weight-bearing: 27.5% did not comply

Chiodo and colleagues (JBJS 2016;98(18):1563–7) followed 51 patients told to remain strictly non-weight-bearing in a short leg cast, with sensors retrieved when the cast came off, on average 24.3 days later. Fourteen of the 51 — 27.5%, 95% CI 15.2–39.8% — were non-compliant. These were not patients who had misunderstood; they had been instructed explicitly.

Partial weight-bearing: 37.5% complied, and instruction made no difference

A partial-weight-bearing analysis of instrumented patients found that of 40 patients under a loading restriction, 25 could not follow it — a compliance rate of 37.5%. The study also tested whether post-operative instruction influenced real loading. It did not, to any statistically significant degree (p = 0.39). Forty-nine patients were instrumented in total (PMC8732824).

At a trauma centre: 31% of steps in range

Ruiz and colleagues (Orthopedics 2014;37(6):e552–6) measured the proportion of individual steps falling inside the prescribed touch-down range. At discharge, 31% of steps were in the acceptable range across 21 patients; at first follow-up, 27% across 18. The study also recorded how patients had been taught: verbal cues for 87% of them, a bathroom scale for 1%. Small numbers, so treat the percentages as indicative rather than precise — but the direction is the same as everywhere else.

Why instruction alone does not work

The problem is not motivation. It is that kilograms are not something a person can feel. Asked to keep a foot at twenty kilos, you have no internal sense of what twenty kilos is, no way of checking during the day, and no signal at all when you drift. The standard teaching aid — standing on a bathroom scale and pressing until the needle reads the right number — is a static, single-moment demonstration of a dynamic, all-day task. It is roughly like being shown the speedometer once and then asked to drive at 50 for six weeks with the dashboard covered.

Compliance also decays as pain resolves

Adherence is not fixed over the restriction period. In one cohort, non-adherence rose from a single patient in week one to 11 of 14 by week six. The pattern makes intuitive sense: early on the limb hurts, and pain enforces the restriction. As pain settles, the only thing left enforcing it is memory of an instruction given weeks earlier — and by then the limb feels fine to stand on.

This matters for when to look. A check at the first post-operative visit catches patients at their most compliant.

What continuous measurement changes, and what it does not

What sensor insoles add is visibility: a record of how much load actually went through the foot, across the whole day, rather than a self-report at the next appointment or a one-off measurement in clinic. That record can be looked at by the patient and shared with whoever is following the recovery.

What it does not do is intervene. Stride One does not cue, correct, coach or alert during walking, and Ceriter makes no claim that it improves adherence. The published evidence above describes a measurement gap. Closing a measurement gap and changing behaviour are separate questions, and the second one is not something this device claims to answer.

What Stride One does and does not do

Stride One is a monitoring device. It records how load is shared between the feet, how the foot rolls through each step, and how pressure is distributed across the zones of each foot. It gives you, and anyone you choose to share it with, a record of how those things change.

It does not diagnose anything, detect any condition, predict any outcome, or tell you what to do about what it shows. It does not measure skin temperature, gait speed, step length, stride length or step width. It does not replace an appointment, an examination or your clinician’s judgement.

Sources

• Chiodo CP et al. Patient compliance with postoperative lower-extremity non-weight-bearing restrictions. Journal of Bone and Joint Surgery 2016;98(18):1563–7.
• Partial weight-bearing compliance, instrumented insole study, 49 patients instrumented. PMC8732824.
• Ruiz FK et al. Adherence to postoperative weight-bearing restrictions. Orthopedics 2014;37(6):e552–6.

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