'Knees' in the Bible

Then a man with a serious skin disease came to Him and, on his knees, begged Him: “If You are willing, You can make me clean.”

Seeing Jesus from a distance, he ran up and bowed down before Him [in homage];

Now as Jesus was starting out on his way, someone ran up to him, fell on his knees, and said, "Good teacher, what must I do to inherit eternal life?"

And they smote him on the head with a reed, and did spit upon him, and bowing their knees worshipped him.