Foam rolling is used in sport and rehabilitation to affect range of motion, performance and recovery. Understanding the science of the physiological effects of foam rolling will have a positive effect on how, when, if and how often we use said implement.
Terms like myofascial trigger points, myofascial release, viscoelastic properties of tissue, fascial adhesions, thixotropy effect, piezoelectric effect of mechanical stress, cellular responses, fluid flow, collagen remodeling, changes in elastin, fascial inflammation all have been proposed and investigated in the literature as underlying mechanical and neurophysiological mechanisms and reasons for the desired/or outcome of the rolling modality. But as it stands these mechanisms are still being investigated and the physiological potential benefits of foam rolling are not fully understood - based upon the most current academic research.
As recently as June 29th, 2019 the Journal of Sports Medicine published, “Do Self-Myofascial Release Devices Release Myofascia? Rolling Mechanisms: A Narrative Review.” Their findings, “This review submits that there is insufficient evidence to support that the primary mechanisms underlying rolling and other similar devices are the release of myofascial restrictions and thus the term "self-myofascial release" devices is misleading.”
There are important considerations and terms that one may research to heighten their understanding of what is occurring when applying mechanical rolling prior to exercise.
When rolling we effect low-threshold mechanoreceptors including muscle spindles, Golgi tendon organs and joint receptors. They provide sensory information, which is essential to the accurate performance of complex movements.
Mechanoreceptors also derive information from external stimuli such as pressure, vibration, touch and sound. They are specialized neurons that transmit mechanical deformation information into electrical signals. Stimulation of these receptors results in muscle contraction about the joint as an adaptive control to sudden movements of acceleration or deceleration.
Activation of tactile feedback from foam pressure can influence efferent sympathetic outflow to skeletal muscle, that is, neural impulses away from the central nervous system and towards muscles to cause movement.
Muscle stimulation by rubbing influences activity of the endogenous opioid system, which modulates the perception of effort. The brain is also getting motor feedback from the agonist muscle being stimulated, both which result in more power output.
We know that if you foam roll only one leg the rate of force develop drops in both legs in the first 0-50 milliseconds and that if you do a leg extension, foam roll and do another you get less repetitions than you would if you just rested.
A wide range of physiological functions are occurring at once during the action of administering pressure on muscle. At the beginning of an exercise or activity massaging can/or could eventually lead to excess peripheral muscle fatigue.
Foam rolling has become commonplace and is used for various purposes, warm-up, recovery, range-of-motion, pain reduction and more. Continual study of this relatively simple activity that has far reaching complex and synergistic resultants will give us the knowledge necessary to appropriately and correctly use this exercise tool.