I don't completely remember how monk was in 1.0. But they no longer require to hit the targets from the front any more.
You generally use 6 skills:
Dragon kick (increased potency on flank)
Twin snakes (increased potency on flank)
Snap punch (increased potency on flank)
Bootshine (guaranteed crit on back)
True strike (increased potency on back)
Demolish (increased initial potency on back, has no effect on the DoT)

Dragon kick, Twin snakes, Snap punch and Demolish will grant you the additional effect no matter which side you hit it from.

It may not seem like boxing anymore (as pugilist had a street-like fighting style where you brutally maul someone's face). It's more like martial arts as of 2.0. To optimise your dps as a monk, you need to be able to reach the proper side each time in specific forms - There are 3 kind of forms, certain skills can only be used in specific forms or get additional effects when used in that form.