To be very effective it had to sound like a punch

The same concept applies to sign languages. In American Sign Language, signs for "defacation" or "intercourse" are often the same when used in medical settings and on the street. Where English differentiates appropriate terminology and expletives by expanding the lexicon, ASL simply modulates a single sign to cover the range of use. Jerkier movements, quicker movements, and a mood-appropriate facial expression are all one needs to convert a sign used in an anatomy class to a Class A expletive.

(Sorry if I've over-citing sign language in recent posts)