Do you know these words?

• あしを　ひろげる

  to move one's legs apart

• うでを　だす

  to put out one's arm

• おろす（ずぼんを〜/ぱんつを〜）

  to take down (one's pants/underwear)

• こしを　あげる

  to raise one's rear end ; to raise one's lower back

• こしを　うかす

  to rise one's lower back