Thread: Thumbing and Heeling

I was looking at a chart of a target and it indicated what caused the misses around the bullseye. example: if you are missing at 12 o'clock, the usual cause is "Breaking wrist up". At the 2 o'clock miss it stated that "Heeling/Anticipating Recoil" was the cause and at 3 o'clock- "Thumbing". What is Heeling and Thumbing mean? Thanks in advance to all the knowledgeable ones!