flexure vs dorsiflexion

flexure and dorsiflexion both are nouns.

Word	Noun	Adjective	Verb	Adverb
flexure	Yes	No	No	No
dorsiflexion	Yes	No	No	No

As nouns, dorsiflexion is a hyponym of flexure; that is, dorsiflexion is a word with a more specific, narrower meaning than flexure:

flexure: act of bending a joint; especially a joint between the bones of a limb so that the angle between them is decreased
dorsiflexion: the act of bending backward (of the body or a body part)

Other hyponyms of flexure include flex.

flexure (noun)	dorsiflexion (noun)
act of bending a joint; especially a joint between the bones of a limb so that the angle between them is decreased	the act of bending backward (of the body or a body part)
an angular or rounded shape made by folding
the state of being flexed (as of a joint)