I have been troubled by this for over ten years on and off- it plays up a fair bit after I have played around five gigs back to back and results in shooting pain up my forearm.
I also from time to time have what they call trigger finger where the fingers in my right hand can lock up from the tendons getting trapped if I hold for example a petrol pump and sometimes in the morning when I wake up, my right hand is closed till I work it loose and the tendons make thwack noise when they release- Horrible and gut wrenching!
I have been treated for it with steriod injections on several occassions in the joints from the palm of the hand! This works for a period of two years or so.
This first happened the day after I prunned mt very big overgrown hedge with hand shears....I think playing just agrevates it.
I use switch my grip on the sticks during gigs now a lot nearly every song in and effort to avoid this and it seems to work in the main.
I had in the past been offered an operation to free up the tendons but declined and the recovery time was around two weeks and thats a lot of missed work!
So just a warning- if you play a lot- dont do too much work that involves your hands gripping time after time, pace your self and save your tendons...you wont feel the hurt at the time but it may show up later and cause grief for years!
Take care of your hands guys and gals!