gastrocnemius
noun [ C ] medical specialized uk/ˌɡæs.trəʊˈkniː.mi.əs/ us/ˌɡæs.troʊˈkniː.mi.əs/ gastrocnemii /ˌɡæs.trəʊˈkniː.mi.aɪ/ /ˌɡæs.troʊˈkniː.mi.aɪ/
（拉丁语，用于医学术语中）腓肠肌
the outer calf muscle that goes from the back of the knee to the heel
Leg cramps cause shortening of the gastrocnemius muscle in the calf. 腿部痉挛引起小腿腓肠肌收缩。