'Joints' in the Bible

Then the king's countenance was changed, and his thoughts troubled him, and the joints of his loins were loosed, and his knees smote one against another.

and not holding fast the head, from whom all the body, ministered to and united together by the joints and bands, increases with the increase of God.

For the word of God is living and operative, and sharper than any two-edged sword, and penetrating to the division of soul and spirit, both of joints and marrow, and a discerner of the thoughts and intents of the heart.