I've been using these for a couple of weeks now and they're working pretty well for me.

The first couple of times I used them my arms ached pretty bad for a couple of hours after, and I had tingling in my surgical arm, so I waited a couple of days before I used them again. Then I did them for a shorter period of time and it was OK. As soon as I feel tension building up in my arms, I stop, and put them away.

My coordination is getting a little bit better every day. It's like Losinghope said, it's a lot easier to go in one direction than the other. At first I could't do it at all but I'm gradually getting it.

I don't think these would be good if you're in a lot of pain, but if you're doing good, they might be helpful to get some of your finger dexterity back.