tendinitis is caused when wrong grip is being used and all the shock of the wood comes straight to ur wrist and the whole shock is spread over ur wrist tendens (or something like that lah ah)
currently there's no cure for tendinitis, just operation to make it feel better so i guess what the donnas drummer has is something permanent unless they have found a cure to it already.... so practise good habits/grip.. i'e wrists and fingers and hold ur stick 2/3 back from the center...
ur fulcrum is important too and also don't bury ur stick when hitting something... all u want is ur stick to do your work for you so let it rebound!!!
no rebound = tendinitis = operations!!!
also, use straight SOLID WOOD and same weight sticks....
recently i bought a peace 7a jazz baby sticks and from the naked eye it looks good but i didn't try it out since it looks good.. but when i tried to practise something on it, immediately after one stroke, i can feel all the shock on my wrist - which means the wood is NOT SOLID and this could be a cause for tendinitis too....
and when i roll it on a flat surface, the tip wobble which means it's not a straight wood so peace sticks are NOT GOOD!!! u've been warned
get sticks from major manufacturers as they have computer balanced them and their straightness and wood solidness is there even though u have to pay like 15 a pair. (9 dollars a pair during SL sale) be it vic firth, vater, or promark (so called the big 3)
and for TS, since ur two limbs can't be used atm, u can do air pedalling
have a speedy recovery.