髀

周髀算经

zhōu bì suàn jīng

Zhou Bi Suan Jing, or Chou Pei Suan Ching, one of the oldest Chinese texts on astronomy and mathematics

拊髀

fǔ bì

to slap one's own buttocks in excitement or despair

搏髀

bó bì

to beat time by slapping one's thighs