1
legs and loins;lower body
彼は息子達と一緒に遠くまでハイキングに出かけた時、体調が思わしくなかったので、その翌日、足腰が痛くて思うように動けなかった。
He was out of shape when he took a long hike with his sons, and he was stiff and sore the next day.
2
foundations;underpinnings