thumb hurts

[JackWhite]

hey fellow bass players! i think ive got quite a problem with my thumb.

ive got very small hands so its very nice for me to have a new fender jazz bass instead of my old squier p bass but i had to notice that ive got the same problem on my j than i had on my p!

the problem is:

if i play riffs where i have to span my left hand (im a righty) very wide, my thumb (which rests on the neck) starts hurting. but thats not always the case. hmm how could i quite explain it?
e.g. i play a typcial country walking bass in Amaj (root, 3,5,6,8,6,5,3) over and over again with quite a tempo. my thumb starts to cramp and its so painful that after about 2 or 3 mins i almost have to stop playing that riff because it hurts that much.

here on the technique board i found a lesson called the spider. thought this would help me with my problem. but its the same there! d+g string work for a while. a+g string start hurting very soon. and e+g string = cramping immediately!

do i just have to work hard at it for a while and my left hand will get used to it or is there any practice routine i can do to stop that cramping/pain?

tipps and lessons would be VERY appreciated.
thanks in advance from austria/vienna
jack

edit: i also noticed that my thumb seems to be pressing REALLY HARD on the neck. im selftaught and im starting to get afraid that ive learned myself quite a wrong left hand technique... suggestions?

[Deacon_Blues]

If you think you're pressing too hard with your thumb, that's probably the issue. Try playing for instance a scale without any support from the thumb, use your right arm instead as a support. This is of course not how you should play, but should show you how little force actually is needed to press the strings.

Try lowering the action of your bass too to reduce the force necessary to press the strings. If you don't know how to do that, check the setup and repair forum. There is probably all answers on that.

And... keep practicing that spider. It's good for the coordination and will build more strength in your fingers.

[Joe P]

Bass setup!

Joe

[JackWhite]

heya. thx for the answers.
ive got quite a low action. on my jazz and on my squier p where im gonna be practicing the spider the next few days/weeks (if its not too harmful ) being comfortable on the p can never be bad for the j

think im just gonna try to get that crampiness away and be more relaxed. hopefully the spider can do that for me.