Where does “短内転筋” come from?

短内転筋 (Japanese) comes from Japanese 内転筋, from Japanese 内転, from Japanese 内, from Middle Chinese 內.

短内転筋 (Japanese): an adductor brevis

Definitions

短内転筋 traces back through two separate lines of ancestry.

Step	Language	Word	Meaning
1	Japanese	内転筋	an adductor
2	Japanese	内転	adduction
3	Japanese	内	inside, within; between, among; while, during,...
4	Middle Chinese	內	—

Step	Language	Word	Meaning
1	Japanese	短	fault, weak point; minor
2	Middle Chinese	短	short