'Joints' in the Bible

Then the king’s face grew pale and his thoughts alarmed him, and his hip joints went slack and his knees began knocking together.

and not holding fast to the head, from whom the entire body, being supplied and held together by the joints and ligaments, grows with a growth which is from God.

For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart.