Hi Maa

Depends on which machine you're talking about - there are small, hand-held machines that I really don't believe are too effective at all. Then there are much larger machines, like the Powerplate, which do have SOME evidence supporting their use. The problem is that the way they're used, in terms of duration, timing, method, is all important and so to get one that you'd use on your own is a real risk. The second point is that there's not that much evidence that they work better than normal supervised rehab - the sort of thing that you would do with a physio. They may often be part of the physio treatment, to help with strengthening, but have not yet been shown to replace it.

So the point is that considering you've just had an operation, you might wish to consider seeing a biokineticst or a physiotherapist and have them guide your rehab. I don't even know what the problem was, so to suggest exercises would be quite reckless and probably incorrect anyway. So instead of spending money on a machine that might work, rather invest it into seeing a professional to help your rehab along.

Good luck