There are my legs(這是我的腿). I walk and run with my legs(我用腿走路和跑步) is a thigh(這是大腿)
Thigh is the upper part of the leg(大腿是腿的上部),which connects the hip and the knee(連接臀部和膝蓋)
This is my calf(這是我的小腿肚),calf is the back portion of the lower leg(小腿部是小腿的後部).