The euphemism treadmill, as far as I understand, goes like this;

1. Science comes up with a term for something or some one.
2. People start to use that term as a slur.
3. Science comes up with a new term because the old term has been tainted.
4. People add the new term to the list of slurs. 3 Science faithfully obliges by thinking up a new term. Surely, no one will turn this into a slur!

Oh boy, have I got news for you, 'jerk' is an ableist slur akin to 'spaz'.

jerk(n.1)

1550s, "stroke of a whip," from jerk (v.1). Sense of "sudden sharp pull or twist" is by 1570s. Meaning "involuntary spasmodic movement of limbs or features" recorded from 1805.

And yet you were rude to others trying to help you out by giving their understanding of the term, guess we are all impolite, jerks here.