Foam rolling is very popular these days. You see them at your local gym, on the sidelines of NBA games, and physiotherapists recommend them all the time. But how exactly does foam rolling work? Well, the short and rather surprising answer is: we don’t really know.
The Benefits
The good news is we know that it does work. One of the major benefits of foam rolling is that it increases the body’s range of motion and flexibility without reducing muscle strength and performance. The same cannot be said for static stretching, which has been shown to increase flexibility but with a resulting decrease in muscular strength, thus impeding the body’s ability to perform at its best (you may have heard people say that you shouldn’t stretch before a game or sporting activity, and this is why!). So foam rolling before you work-out, or before a big game is definitely a better alternative to static stretching. There is also evidence to show that foam rolling can decrease post-exercise fatigue perhaps allowing longer work-outs and therefore increasing strength gains, while at the same time reducing dreaded delayed onset muscle soreness (or DOMS for short).
What DO we know about how it works?
If you are anything like me though, just knowing that it works isn’t quite enough. I want to know HOW it works so that I can better educate my patients, and understand my own body a little better. There are many different thoughts on this issue, with strong believers for each explanation. I’ll share the gist of some of them, and talk a bit about the explanations I like best.
Lengthening fascia?
The average person believes, as well as some professionals, that foam rolling effectively increases the length of our fascia (in short, fascia is the connective tissue that encases our muscles and forms a solid, connected network throughout the body). But our fascia isn’t weak, super pliable stuff: it’s tough. So is it really possible to make permanent change to the structure of fascia just by rolling on your foam roller? Think about it, if this were true, every time you sat on a hard surface your fascia would deform. In fact, studies show that the amount of force required to produce lasting changes in fascial structure is well outside of what humans are capable of producing. So when you are foam rolling your IT band (a giant band of fascia), no, you are not increasing its length.
There is however some evidence that shows that pressure applied to the mechanoreceptors (receptors that detect pressure and distortion) in fascia can cause a change in tone, or some amount of relaxation of the muscles connected to the fascia. This could explain the relaxation felt by the pressure of foam rolling.
Breaking up adhesions?
Another common explanation for the effectiveness of foam rolling, is that it breaks up adhesions in the fascia. These adhesions form between fascia and the muscles connected to the fascia preventing smooth gliding between muscle groups, thus causing decreased range of motion. This theory is definitely plausible, although there are still a lot of unanswered questions here. First, it is unknown if these adhesions are thin enough to be broken up with the force of foam rolling in the first place. Foam rolling also allows only direct, non-specific, blunt force, rather than force from an oblique angle which logically would help increase sliding. Further, one bout of foam rolling isn’t a cure. If the adhesions are being broken up, why do you have to keep foam rolling, multiple times per day? So maybe there is something to this, but there isn’t enough research yet to know.
Changing blood flow?
Ok so we haven’t come to any definitive answers yet, but there are two theories that I like. The first explains the post-exercise effects, and simply implies that foam rolling reduces stiffness in arteries and improves blood flow. DOMS typically presents as pain and discomfort a day or two after exercising, and is caused by the breakdown of muscle structure from heavy loading. By increasing blood flow, the body helps repair damaged muscle quicker by removing blood lactate, increasing oxygen delivered to the area, and reducing swelling, thus reducing DOMS. Foam rolling may work to increase blood flow in several different ways. First, by putting pressure on an area for a short amount of time, you are actually compressing the blood vessels. The body responds by increasing chemicals that cause dilation of the blood vessels. When the compression stimulus (foam roller) is removed, the circulating vasodilators continue to cause increased blood flow. The blood vessels themselves also become more elastic, although the mechanism behind this is not clear.
Pain gating?
The other explanation I really like that isn’t often talked about, is the ability for foam rolling to reduce the “volume” on nociception (the body’s signal for danger that results in pain) in the nervous system. This concept is complicated and warrants a whole blog in itself, so here is a brief explanation of what I mean. When you encounter something that your brain feels is dangerous (i.e. you step on a nail), a signal is sent via your nervous system for the body to start feeling pain. This pain signal can be blocked, or reduced, explained by the Gate Theory. Essentially, the signal will only get to your brain if this nervous system “gate” is open. The “gate” can be closed by the introduction of another stimulus. This is why, for example, if you get hurt and you vigorously rub the area, you actually feel less pain: the rubbing stimulus has overpowered the pain stimulus and closed the gate. Foam rolling makes you feel “good pain” meaning endorphins are likely released, and the real pain you felt from your sore muscles is temporarily blocked. This in turn allows your body to move more, meaning your functionality is increased after rolling, and performance may be improved. Many people feel like foam rolling actually lets their whole body move more freely, not just in the spot they rolled, which supports the notion that the rolling stimulus has blocked pain from other areas of the body as well. This is also one of the methods by which massage and acupuncture work to help ease pain.
So the answer to HOW does foam rolling work? Well, let’s just say it’s unclear. But there is a reason you see those little rollers everywhere: they work! So no matter your beliefs or understanding of the subject, find out how foam rolling may be able to help you.
References
Chaudhry, H., Schleip, R., Ji, Z., Bukiet, B., Maney, M., & Findley, T. (2008). Three-dimensional mathematical model for deformation of human fasciae in manual therapy. The Journal of the American Osteopathic Association, 108(8), 379-390.
Cheatham, S. W., Kolber, M. J., Cain, M., & Lee, M. (2015). The effects of self‐myofascial release using a foam roll or roller massager on joint range of motion, muscle recovery, and performance: a systematic review. International journal of sports physical therapy, 10(6), 827.
Okamoto, T., Masuhara, M., & Ikuta, K. (2014). Acute effects of self-myofascial release using a foam roller on arterial function. The Journal of Strength & Conditioning Research, 28(1), 69-73.
Want to find out if foam rolling is something you should be trying? Reactivate Physiotherapist (Resident) Carly Litchfield would be happy to talk with you.
