Knee
noun
ひざ
膝 (ひざ) Knee
膝頭 (ひざがしら) Kneecap, Patella
膝小僧 (ひざこぞう) Kneecap
肘 (ひじ、not on WK) Elbow
脛 (すね、not on WK) Shin
小僧 (こぞう、not on WK) Youngster, Boy, Kid, Brat
For Shin 脛 since it's not on WK: Construction 工 when the moon 月 is out will soon すね lead to a figurative flood (radical) of Shin 脛 injuries and will ground 一 everything to a halt.