I would be speak to the people doing the job about practicality of poles as a first step. Depending on what they are doing there may be no need for them or they may even be a hindrance if they are carrying tools in their hands. I've done hill walking and outdoor roles in the past. Provision of decent wet weather gear and footwear was the main priority back then. Poles would just have gotten in the way and I was normally carrying instruments or tools.

I think Jimothy999 has probably covered it. Consultation is the key really.

You ask for specific lessons learned, so some of what follows may help? I did some pro bono work a while back with an organisation that operates a weekly walk across rough ground for visitors of all ages on a remote-ish Scottish island. They'd experienced kick-back from local NHS people re the occasional need for a helicopter evacuation when someone tripped and broke an ankle, and their resulting revised risk assessment said that walking boots were compulsory. But they didn't have any supporting date to demonstrate that all such falls were to persons wearing footwear with no ankle support - indeed there was anecdotal evidence to the contrary. To me and some others their controls decision was a bit too simplistic - from web searches and a range of personal experiences, ankle support is important, especially for people who don't do much of such walking (like many of the visitors), but poles are another option, and also there are many experienced walkers who use lighter footwear that's suitable for reasonably rough ground but has no ankle support. Some commercial walking holiday providers advise boots for certain walk grades, but their websites don't say it's mandatory. Also there are other commercial organisations in that area of Scotland who take boatloads of casual visitors to an even more remote island, but have no 'rules' about footwear, and havn't had the same problems with occasional NHS evacuations. Based on this research, I encouraged to organisation to consider boots OR poles, and the originators of the RA thought that a good idea - though I don't know what actually happened the following season and subsequently So, in an employment situation I can see no problems with poles. In the past couple of years I've begun to use poles myself when I feel a bit tired on a longer walk, and especially for downhill - which is harder for anyone with a knee problem. There are no real downsides - you can have something small in one hand if needed, so as far as I'm concerned they are 'reasonably practicable', as they are no too expensive. However consultation about whether use is compulsory or just advised is key. Situational awareness is also key, for example if you want to blow your nose - on what sort of ground do you stop, and when is it OK to just keep walking!!

.... on the other hand Invictus they may have their carers accompanying them. NLivesey; we need to know a bit more about the task and people involved to make sensible comments or offer experience. Are these novice walkers or experienced, do they have their own equipment or is it 'work wear' and a ppe situation? Or will they use as a weapon to play and swordfight? If this is a work situation then sensible training should be included otherwise they might not be used properly and make the situation worse (eg I change the height every few minutes depending on what the terrain is like and how I am using the pole to either support/save energy, reduce shock stress or navigate an awkward rise/fall. I suspect that very few people who use them have ever been shown how to get the most from them (again this isn't just about safety and health - it is also operational efficiency). Nanny state maybe, but professional outdoor people can't just be left to machismo hopefulness that they will know these things - especially when starting out. Personally speaking I would not be without a (single) pole on a long walk. On the flat I get about 15-20% energy saving, climbing and decent is both easier and safer (imho) as tungsten tip provides a very secure point on the slipperiest of rock. I can fend off adders, use as a signal flag pole, pitch an emergency bivie and toast marshmallows if required. I can prod riverbeds to find secure footing, brash away brambles and 'stingers' and mount a camera for a selfie. If not needed it is so light it is simply put on to my day sack. Most are ergonomically designed for walking, but grip varies and is important for daylong use to avoid blisters. I would approach manufacturers and ask for clinical sales data/medical research they have done. Maybe also try ramblers to see if they have commissioned any research (even non conclusive member surveys would be useful for your decision). Regarding footwear - mostly agree with the above but I like and try to buy Vibram soles for hiking, whoever makes the boots. Very Tough and nonslip - my opinion only. I do think this would be an area where ppe policy allows people a choice - most who work in such areas recognize the value of getting good kit. I think that any hiker should have minimum safety essentials and in my view this may form part of that kit.