lie vs change posture

lie is a noun but change posture is not a noun.

Word	Noun	Adjective	Verb	Adverb
lie	Yes	No	Yes	No
change posture	No	No	Yes	No

As verbs, change posture is a hypernym of lie; that is, change posture is a word with a broader meaning than lie:

lie (noun)	change posture (noun)
a statement that deviates from or perverts the truth
position or manner in which something is situated

lie (verb)	change posture (verb)
tell an untruth; pretend with intent to deceive	undergo a change in bodily posture
be lying, be prostrate; be in a horizontal position
assume a reclining position
be located or situated somewhere; occupy a certain position
originate (in)
have a place in relation to something else
be and remain in a particular state or condition