There is a calculation almost no hospital makes, and it is among the heaviest.
A patient is admitted for pneumonia, a fracture, a decompensation. The problem that brought them in is treated. And meanwhile something else happened: they spent days in bed, and the loss of function that causes can be larger and longer lasting than the acute episode.
The numbers, with the caveats they deserve
The bed-rest literature is consistent in direction and highly variable in magnitude, so ranges rather than certainties:
- Strength loss of roughly 1% to 3% per day of bed rest, with higher figures reported in older people.
- Muscle mass loss that accumulates quickly in the first days, and which several studies put in the order of several percent after a week in immobilised older adults.
- Recovery is not symmetrical. It is frequently cited that each day of absolute bed rest may require up to two weeks of reconditioning to return to baseline.
That last point changes the conversation. It is lost in days and regained in weeks, and what goes first is precisely the antigravity muscles — the ones for getting out of a chair, climbing a step, standing. Which are the ones that decide whether someone goes home or goes into an institution.
Where this costs the system money
The bill does not appear under "immobility". It appears scattered:
- More bed-days, because discharge depends on function and not only on the acute problem;
- A worse discharge destination — continuing care or an institution instead of home. It is the most expensive difference of all, and it is often permanent;
- Falls, during the stay and in the following weeks, with what follows them;
- Readmissions, with a patient who left frailer than the illness warranted;
- Care burden shifted onto the family, which nobody books at all.
And none of these lines belongs to the budget of the department where the patient lay still — which is exactly the problem described in whoever pays is not whoever saves.
Why it is so hard to fix
Not through ignorance. Everyone on a ward knows it is better to get the patient up. What is missing is staff time, the scarcest resource a hospital has, and mobilisation consumes a lot of it: two people, ten minutes, several times a day, for something that is not urgent today and whose benefit shows up two weeks later somewhere else.
The second difficulty is adherence. Many patients do not want to. They are tired, in pain, cannot see the point, and guided exercise is boring in a way that helps nobody repeat it.
Where virtual reality fits — with every caveat
Let us be precise, because this is an area where it is easy to oversell.
What virtual reality does not do: it mobilises nobody. It does not get a patient out of bed, does not replace a physiotherapist, does not replace an early mobilisation protocol, and there is no evidence that it reduces length of stay. The best-supported interventions for this problem are mobilisation protocols and physiotherapy staffing. If you have to choose between a physiotherapist and a headset, choose the physiotherapist — we say that as a manufacturer of headsets.
What it may do: make guided movement more acceptable to those who refuse it. The hypothesis, and it is a hypothesis, is that exercise with a visible purpose gets repeated more often than exercise without one — and adherence is half the problem. We have written about adherence to physiotherapy in older adults.
A regulatory caveat that cannot be skipped: support for guided movement is RVer Motion, a module in development and not covered by the Class I medical device registration, which covers the base product. Anyone presenting the module as part of the registered device is misleading you.
And for those who do not get up at all, what exists is a different thing and should not be confused with rehabilitation: comfort and presence, with lying-down mode aligning the horizon for someone reclined.
What to measure, if you really want to know
Do not measure length of stay — it has too many causes and you will never attribute the difference. Measure what is closer:
- mobilisation sessions offered and completed, with and without the system;
- refusals, which is where an effect, if any, shows up first;
- function at discharge with a simple, consistent instrument.
None of these proves clinical effect. All of them tell you whether the thing is being used and whether adherence changed, which is what a pilot can answer — the rest is in the ROI that cannot be proven.
In short
- Lost in days, regained in weeks, and the standing muscles go first.
- The bill shows up in the discharge destination, not under immobility.
- Virtual reality mobilises nobody and replaces no physiotherapy.
- Where it may help is adherence — and the module supporting it is in development and outside the registration.