A fistumba is any injury or mark sustained during the processes of high-fiving, fist-bumping, chest-bumping, etc. Usually bruises, red knuckles, sore hands, etc. From the goofy injuries people get while doing Zumba exercise. This word first aired on the show "A Way With Words" in late 2012 and was called in by a school teacher whose students were using it.
"During band practice, my saxophone solo was harder than usual because of the fistumba on my right hand."