I didn't really want Bree put on one when I went to my yard, but she plods around calmly with the other horses, with her head and neck stretched out nicely and she's a horse that expresses it if she's unhappy but throwing up her head and prancing about. So I'm now of the opinion that the extra exercise will do her good, especially over the winter months.
Don't have a horse walker personally, but at work we do. It is used to keep the polo-ponies 'stiff free' - usually the day after they have played or on a day when all else is hectic when ridden exercise just ain't happening. (lazy mans way!) It is also used for the fittening of the thoroughbred horses going to the sales alongside hand-walking, long lining and lunging. Mainly talking yearlings, but the weaned foals do go on it too to just give a boost for their 'looks' at the sales. (Not what I would do personally, but just saying we do it as part of our job). Foals go on it for 20 mins, yearlings working upto an hour - this year one goes on for a bit longer as he is needing it (says boss), and the polo ponies are on it for an hour too.
At my old job with event horses, they usually went on it for an hour while the stables were mucked out and as a 'warm-up' to ridden work. It can also be used while bringing horses back into work and the time scale of that would depend on how unfit/injured they were/are.
Thanks guys, I'm still undecided about the whole thing! My horse goes in the walker everyday - It was suggested that I do this to give him a nice warm up before work, but now I ride at o'crack sparrows fart and he goes in the walker afterwards and I don't know whether to keep in the walker schedual or not?! I guess another 40 mins of work each day isn't going to do him any harm is it?
They're handy enough to replace in hand walking in some circumstances, such as a big busy yard. But tbh I'm not convinced walking circles for long periods is any good for joints so can't say I'm a massive fan in most cases. I can see the logic in why comp & racing yards have them, but personally I prefer them to exercise other ways. And until someone can provide documented, comprehensive research showing its harmless, I wouldn't be regularly putting a young/unfit horse on one. I wouldn't ride a 20m circle in walk for 15mins let alone an hour with most horses, so why put the same strain on them with a horsewalker. Plus I've always believed walk is the easiest pace to ruin, & the hardest to get back so I'm fussy about what's done in walk.