My bass instructor doesn't seem to think this is a problem and he doesn't have it because he's double jointed but it's been bothering me. When playing up high (10th fret and higher) my thumb has a tendency to turn sideways instead of resting flat. See pics: Is this ok? It seems to be better when I stand and play but generally I sit when I practice. So should I worry about this and try to correct it or should I just let it be? Thanks.