Iwas wondering if there is a certain way you position your thumb behind the neck. rite now i play with my thumb a little above halfway behind the neck. after playing for a little my thumb starts to hurt.
There are a million different ways to hold a guitar and u just have to do whatever is comfortable for u. I do different stuff when I play power chords...like sometimes I let the neck rest in my hand with my thumb sort of over the top of the guitar, that way if something wierd comes up and u need to u can use ur thumb to play notes on the top string. I even use my thumb to play the power chords sometimes. My thumb also tends to hurt when I play bar chords on a crappy acoustic bc the strings are hard to push down. Maybe its partially the guitar?
Crappy cheap acoustics are great, the one I had helped me strengthen my fingers ten fold... then I smashed the ****er.
try searching before you post, there is another thread in this forum with the exact same question... and since I hate repeating myself search for that and whatever it is that I told that guy will go for you too... and btw, its gonna hurt.... its because your fingers arent strong... get a cheap acoustic and the thickest acoustic steel strings money can buy, then bar the shit out of it.... play that thing for about 4 months and your fingers will build enough strength to do an entire gig with nothing but bar chords... good luck