膝を打つ
(膝を屈めるだけの意味なら)to bend one's knees―(礼拝、服従するの意味なら)―bow the knee (to or before god or man)―(屈服するの意味なら)―come to one's knees
to sit knee to knee with one―sit opposite each other
膝にくる
to cross one's legs (tailor-fashion)
to sit knee to knee with one―sit opposite each other
膝を組むこと
ひざを折る
to have a familiar talk with one