ELI5 Muscle Knots - do muscles really get in knots and what causes them?

What is really going on when you get a bump in your back or neck muscle that hurts when you press on it? Do muscles really get knots? How do they form? Why are they not detected in scans like x-rays or MRIs? Why do deep tissue massages sometimes make them feel more sore? What are ways to prevent muscle knots? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: theotherbogart, hearmeroar92, entropynz, iluvtheinternets, shintasama, omanfishesinthesea, littleredbunnyfoot and lsarge442. To the community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: [email protected]