The shoulder has an enormous range of motion.
Boxing although seemingly on one plane works most of the range.
Look at a boxers shoulders, most are equally developed (anterior, medial & posterior).
The anterior is used to punch, the medial to hold their arms up, the posterior to prevent their shoulder exiting it's joint upon impact.
I think an upward punch is called an upper cut :lol:
I like boxing for a training tool, but i'd hate to be a boxer
