'Knees' in the Bible

then the king's countenance hath changed, and his thoughts do trouble him, and the joints of his loins are loosed, and his knees are smiting one against another.

And Daniel, when he hath known that the writing is signed, hath gone up to his house, and the window being opened for him, in his upper chamber, over-against Jerusalem, three times in a day he is kneeling on his knees, and praying, and confessing before his God, because that he was doing it before this.

and lo, a hand hath come against me, and shaketh me on my knees and the palms of my hands.