Burn mark on front of thumb towards tip under skin. Black mark on nail tip, back of thumb. Even cracked nail awhile back. Feels like nail is dragging upon exit of thumb from thumbhole during release. No pressure, stress on fingers, only thumb. Specs, span-4 5/16, thumb-15/16 oval switchgrip with 1/8 fwd 0 lateral. Fingers 1/8 rev both, using vise powerlift grips. Was thinking of going 1/16 more rev in thumb to finish at 1/16 fwd, and going 1/8 more fwd with fing to finish at 0. Hoping this will put more pressure to fingers and not thumb. Any thoughts, help is appreciated.