Does foam rolling and “smashing and flossing” work?

Question

I am the lucky (?) owner of a copy of the book "Becoming a Supple Leopard" by Kelly Starrett. In this book on page 139 he introduces a concept that he calls sliding surfaces:

"To ensure suppleness, your tissues - skin, nerves, muscles and tendons - should all slide and glide over each other".

Further he states: "When you sit for prolonged periods, for example, your glute muscles stick to one another and become unresponsive, which limits their ability to contract."

It sounds somewhat plausible that lack of movement causes these socalled sliding surfaces to not glide so great, but that the muscles starts sticking to each other sound preposterous to me.

Anyway, I would think that the cure for not so great sliding surfaces would be movement, the same way that movement "lubricates" the joints.

But no, the solution is according to Starrett to apply pressure to the muscles using different kind of foam rolls and lacrosse balls etc. He refers to using the lacrosse ball this way as "smashing and flossing".

Even though I am highly skeptical to his explanations, I think these techniques may work to some extent, but not for the reasons he suggest.

I think they could work in two ways:

1. Before exercise. The pressure somehow "numb" the neural system causing the muscles to relax leading to increased range of motion (ROM).

2. After exercise. Improves circulation leading to faster recovery like massage.

Do you have any experience using any of these techniques, and did they work?

I am especially interested in my point 1 above. The idea would be to increase ROM before strengthening the muscle in elonged state by eccentric training ("stretching"). Thereby causing a more permanent increased ROM.

Answer 1

Your #1 would be an "analgesic effect". Kelly's theory is effectively "myofascial release". Have you seen this oldie-but-goodie video: https://www.youtube.com/watch?v=BnYdzaoMyQ8 ? Spina debunks the idea that foam rolling can achieve myofascial release. From your question, it sounds like Kelly is also throwing "nerve flossing" into the mix. Nerve flossing is a term coined by Stuart Mcgill, but as far as I can find, he only used the term in an informal context and he never published research on it. In any case, nerve flossing and myfascial release refer to completely different techniques and should not be conflated.

Nobody really knows how foam rolling works. For example, see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721176/ about foam rolling and recovery from exercise. They suggest increased improved blood circulation, but also make clear it is only a theory. At this point, everyone is equally entitled to their own theory, except that myofascial release seems the least plausible to me.