What is a “knot” in a Muscle?

If somebody gives you a definitive response to this, then know that it’s just a guess because nobody actually knows the answer.

That being said there seem to be a couple of different prevailing theoretical camps: In the first camp, experts believe that they are contractions within the muscle caused by muscles tensing repeatedly. The second camp disputes this citing lack of ability to see these contractions on a scan. This camp believes that the cause is neural and a product of irritated nerve endings.

Someone was feeling knotty…