Further to the above posts might it be possible to deliver balance perturbation training to older adults on a large scale ,prevent them from becoming injured by falls and thus reduce prolonged periods of morbidity ?
With that in mind the following ,or a version of it ,might be of some use .
With regard to balance perturbation training the effects of which have been shown to last for a considerable period of time I wonder if the bus idea might be extended .
Some balance training/testing systems include a platform on which a subject stands which is then moved at random to produce balance disturbance and subsequent recovery . All such systems also have safety harnesses to prevent the participants actually falling since safety is a key issue in such training which should only be delivered by qualified individuals .
But why not the following .Instead of delivering training to one individual at a time why not 8-10 and why not bring the testing/training lab to the people to be trained . This is were the bus comes in .
The bus /lab would need to be capable of transitioning from a road going vehicle to a balance training lab possibly along the following lines .
1 Take one bus and remove all seating apart from the drivers seat and two fold away “team member ” seats.
2 Create 8-10 spaced balance stations complete with overhead safety harnesses.
3 Equip bus with a very low gear so that small movements of the bus of say 6 inches can be easily delivered .
4 Have an on off suspension system -on for transit to site -off for training on site .
5 This would be a bit trickier but fit bus with a wheel base that behaves as that of a normal bus during transit but which can be manipulated a bit like the wheel base of a shopping trolley when on site so that perturbations may be delivered in any horizontal direction .(My understanding is that perturbations which move the FBOS forwards, causing a sensation of falling backwards , are the most effective at improving balance in the type of system proposed )
6 Fit bus/balance lab with a computer to control balance training program.

That’s about it . A “Balance Team” might consist of 3 individuals who would travel in the bus /lab to a given destination . The bus would transition into a balance lab by first parking in an appropriately sectioned off area ,switching off the suspension and securing the people to be tested /trained into the safety harnesses at the balance stations . The bus movement program (about 6 inches in any direction) would then be engaged with members of the balance team keeping a close eye on the participants .The trained team would also have the ability to pause the program at any point with safety being paramount .
Research already exists into the levels of balance disruption individuals are comfortable with and so care would be exercised not to exceed these levels.
Obviously 2 team members (one team member would be located outside the bus to ensure the safety of anyone approaching the sectioned off area) cannot accurately record the balance recovery actions of 8 individuals at once so this aspect would be recorded by individual cameras programmed to start recording 2 secs before the planned perturbations and for 5 secs afterwards thus providing a shortened film for later analysis .
You would not attempt any of the above without first ensuring it was completely safe both for those in the bus /lab and for those who might be passing by but if all were tested and passed then, as far fetched as the idea at first seems, perhaps it may have some value .

With regard to the above and the significant retention of the ability of younger and older adults to resist loss of balance after a single session of perturbations I thought the following reference might be of interest –

Learning to resist gait-slip falls: long-term retention in community-dwelling older adults
by T Bhatt – ‎2012 – ‎Cited by 17 – ‎Related articles
Arch Phys Med Rehabil. 2012 Apr;93(4):557-64. doi: 10.1016/j.apmr.2011.10.027. Epub 2012 Feb 18.

Kind regards
Gerrard Farrell
Wilton Street