Whenever I have to describe a shaky movement I find it really hard to pick the right word. More specifically, I never know whether to use wiggle or jiggle. Dictionaries don't help much:
jiggle UK /ˈdʒɪɡ.əl/ US /ˈdʒɪɡ.əl/
to move from side to side or up and down with quick short movements, or to make something do this: If the door won't open, try jiggling the key in the lock.
wiggle UK /ˈwɪɡ.əl/ US /ˈwɪɡ.əl/ informal
to (cause to) move up and down and/or from side to side with small, quick movements: He tried wiggling the control stick but nothing happened. She wiggled her toes in the water. Her hips wiggle as she walks.
From Google NGrams I see some common collocations for both verbs are jiggle cage, jiggle bars, wiggle room and wiggle eyes1. Also, it seems that for body parts such as fingers, toes, or tails2, wiggle is more common than jiggle. Actually, Google Ngrams doesn't return a single instance for "jiggle" with the aforementioned body parts.
If we move on to consider dance moves such as twerking, both verbs come up pretty often. As an example, take Jason Derulo's song Wiggle, or this video where a fitness instructor says "let the booty jiggle".
So, is there any difference in usage between "jiggle" and "wiggle"? When should I use each? Are there any instances where only one is correct or natural-sounding and the other is not?
1: Some alternative expressions are wiggly eyes or googly eyes.
2: Even though wag is far more common to describe the movement of a tail, it seems wiggle isn't unheard of.