After 18 months as a WC i'd started to get a lot of pain with my right wrist prior to this but just used to put one of those 'warm heat 'em up in a microwave sausage things' on it. The pain got worse over time and to be honest I was worried I was going to have to stop. I'm going to describe where on my wrist the pain was.
Sit down at a desk or table and place your right hand palm down. Relax the muscles and then slide/waggle your thumb whilst keeping it on the desk. You'll see two tendons move, a large one above a more difficult to see smaller one. It was these two that were giving me the pain.
The doc told me I needed to rest it for at least a year or better still 2! I said I was going to try and get a brace for it - she kinda laughed at me and said fair enough.
I bought a couple of these:
http://www.amazon.co.uk/gp/product/B00021XRP2/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1 and I swear the pain went literally overnight. It was like a miracle. I've had no pain since though I've gone through 6 braces as they get manky and wear out!
I can only put it down to the action I use when wfp-ing. I try now to cup the bottom of the pole in my right hand (I'm right handed). The braces have an aluminium strip running the length of the palm and - importantly - on the top of the hand (it's called a "dorsal stay"). These prevent you from moving your hand in a way that causes the problem.
Time to get used to working with the brace on - around 20 mins

Time taken to write out a 'Your windows Have Been Cleaned' slip - around twice as long as before lol!
If you've got the same or similar problem then I recommend you give these braces a try.