I constantly recommend the foam roller to clients, class participants, friends, and especially runners and cyclists. I use the roller and other self myofascial release tools often and I can feel a difference in pain and function afterwards. When people ask why or how it works, I have found my explanation to be a bit lacking. I’ve searched around and there isn’t a lot of scientific research done on the foam roller, but there is a decent amount on myofascial release in general. It’s much more complex than just saying massage relaxes your muscles and feels good (although it does!). In order to understand how and why myofascial release works, it is important to understand the structures involved. As always, I’ve tried to make it as easy to understand as possible.
Fascia is a connective tissue in the body, and the term myofascial refers specifically to the connective tissue that surrounds the muscles (myo). Each muscle is enclosed in its own fascial sheath, and the fascia of adjacent muscles are connected to one another. In addition, some groups of muscles that function together are surrounded by an addition fascial sheath. The fascia of these groups of muscles are then connected to other adjacent muscles or groups of muscles. This web of connection exists throughout the body. While fascia does not contract on its own the way muscles do, or have direct connection with the circulatory system, it is extremely important for transmission of force from one joint or body segment to another, shock absorption, joint stability, and muscle tone.
Fascia is comprised of collagen fibers that are orientated in a relatively parallel fashion. Trauma or dysfunction of the tissue can cause disturbances in its function, which will be addressed later. A liquid-gel type substance called ground substance fills in the space between collagen fibers. The ground substance varies somewhat depending on the tissue the fascia is surrounding, but is generally comprised of water and proteins.
Also within the fascia are a variety of receptors that sense mechanical (movement, tension or pressure related) and biochemical changes. One type of mechanoreceptor is the Golgi receptor. These are found all along the myofascia, but are commonly known for their presence in tendons as Golgi Tendon Organs. These receptors sense the force of contraction of the muscle. Other mechanoreceptors are called Ruffini and Pacini corpuscles. These receptors respond to short- and long-term pressure changes and vibration. A third group of mechanoreceptor is called interstitial myofascial receptors that are found within both muscle and fascia tissues. These receptors sense temperature, pressure, pain and chemical changes. This could explain how muscles can hurt even when they are not being moved. Pressure applied to the muscles will stimulate these mechanical receptors. Slow, steady pressure has been shown to decrease blood pressure, muscle tone/tension, and emotional arousal, while quick or sharp pressure has been shown to cause muscle contraction, most likely by stimulating a reflex response. If you’ve ever rolled quickly over a trigger point on the foam roller you probably experienced this kind of sharp contraction, rather than when moving slowly and allowing the muscles to release as you go.
So now that we have some understand of what the structures are, we are well equipped to next understand what problems can occur to cause excessive tightness, pain, and trigger points. Thanks for reading, there’s more to come!
Schleip, R. Fascial plasticity-a new neurobiological explanation: Part 1. Journal of Bodywork and Movement Therapies, 2003. 7(1) 11-19.