'Joints' in the Bible

But one man drew a bow at random and struck the king of Israel in a joint of the armor. So he said to the driver of his chariot, “Turn around and take me out of the fight, because I have been seriously wounded.”

Then the king’s face grew pale, and his thoughts alarmed him; the joints and muscles of his hips and back weakened and his knees began knocking together.

From Him the whole body [the church, in all its various parts], joined and knitted firmly together by what every joint supplies, when each part is working properly, causes the body to grow and mature, building itself up in [unselfish] love.

and not holding fast to the head [of the body, Jesus Christ], from whom the entire body, supplied and knit together by its joints and ligaments, grows with the growth [that can come only] from God.

For the word of God is living and active and full of power [making it operative, energizing, and effective]. It is sharper than any two-edged sword, penetrating as far as the division of the soul and spirit [the completeness of a person], and of both joints and marrow [the deepest parts of our nature], exposing and judging the very thoughts and intentions of the heart.