Questions & Answers about Передпліччя між ліктем і зап’ястям.
It is understandable, but it sounds more like a short textbook definition, caption, or label than a fully natural standalone sentence.
A fuller version would be something like:
Передпліччя — це частина руки між ліктем і зап’ястям.
= The forearm is the part of the arm between the elbow and the wrist.
Or:
Передпліччя розташоване між ліктем і зап’ястям.
= The forearm is located between the elbow and the wrist.
So the given version is not wrong in a learning/chart context, but it is abbreviated.
In Ukrainian, the present-tense verb to be is often omitted, especially in simple statements, definitions, and short descriptions.
So Ukrainian can say:
Він удома. = He is at home.
Literally: He at home.
Likewise, this phrase can be understood as:
Передпліччя [є] між ліктем і зап’ястям.
That said, in this particular sentence, a fuller and more natural everyday version would often use a more specific verb such as розташоване (is located) rather than just an implied є.