> I suppose I _must_ interject on this one. While the masseter (the name of the jaw muscle) can provide the most external force, it isn't necessarily the strongest muscle. It just has the leverage advantage. The strongest muscle in the body would be the heart. It is active nearly constantly, and is extremely difficult to exhaust.

that would make it the muscle with the greatest endurance, then, would it not? It all depends on your definition of the word strong.