Hello, when i play ska my pick seems to keep moving out of my hand and it ends up with my index finger being almost straight. any help?

ive tried jazz 3's , fender medium/thing picks so i think its something wrong with me.

i play with my fingers out and not all balled up
if its a grip issue, try the Dava control picks.
the have like 3 different grip zones, and they hold really well. i use them all the time.
im not sure if its a grip issue, when im playing normal alternate picking and power chords such my index finger stays arced. but when i play ska and sometimes normal chords my index finger starts to straighten out
you are probably doing the picking motion with your elbow and not with your wrist or not holding your pick hard enough
i used to use fender picks and i dropped my pick all the time when strumming but i bought some dunlop tortex picks and i barely drop it anymore.
i used to be a mod, then i took an arrow in the knee.
well is my technique when playing chords wrong, like like my index finger will straighten out quite a bit