I just finished weight panting the hand on this model and I thought it seemed good, but when I moved the hand or arm bone the hand didn't follow entirely. It spiked out like so:
I made sure "Auto Normalize" was on and that the individual fingers were properly painted and the weights didn't bleed onto the other fingers. I selected each finger bone individually and painted around them with a weight of 0. What would cause it to glitch out like this? Is there an easy fix? Having to repaint the fingers would be a pain in the ass.