Pushing Into Muscle: Are We Really Doing What We Think We Are Doing?

We massage therapists are taught a lot about muscles. We also study bones, joints, ligaments, tendons, fascia. We learn a little about physiology, about other systems of the body, and some lip service is paid to the role of the nervous system in the relaxation response and to how the brain mediates the changes brought about by massage. But mostly we pay attention to muscles. We talk about which muscles are tight, find “knots” in them, and “release” them by pushing into them and/or stretching them with our hands, fingers, forearms, and elbows.

For many years, I studied and assisted at seminars about myofascial trigger points, tender points that, when pushed into, will refer pain or other sensations elsewhere. It was believed that they existed in muscles and though much wasn’t known about them, our approach was to locate them, push into them, and somehow this would alleviate the pain that they seemed to be associated with. We weren’t sure exactly how direct pressure created this change. At first the “Gate Theory” was proposed to be the mechanism by which this change came about. [note: scroll down the page on that link to find the segment on the Gate Theory.] Later, it was suggested that TPs were the result of damaged endplates at the neuromuscular junction and that our pressure destroyed them and caused the body to rebuild or repair them. That explanation always troubled me a bit. For one thing, sometimes it didn’t take all that much pressure for a TP to be calmed. For another, I just didn’t like the idea that I was destroying structures in the body. However, there were no better explanations and digital pressure on TPs seemed to work well enough often enough. I accepted that we just didn’t know how it worked and left it at that.

But I still believed that I was pushing into muscle tissue and that somehow that pressure on muscle did something to muscle fibers to release contracture and reduce pain.

Over time, more questions were raised. Gross anatomy class  brought me face to face with evidence that challenged my  assumptions about our ability to “touch” certain muscles. One of the most obvious was the piriformis. Most of it lies inaccessible beneath the sacrum. Through dissection, I saw that only a small tip of it is exposed beyond the sacrum. In addition, what little of it is exposed is deep within the hip, covered by several inches of adipose tissue on even the most slender of individuals, not to mention the skin covering it all. Was it really possible that we could push into the tip of a muscle that was covered either by bone or several inches of padding plus skin? This didn’t make sense but I didn’t dwell on it. After all, it felt like we could do that so I didn’t think about it too much.

 

The role of the nervous system


My Russian Massage teacher Zhenya Kurashova Wine was the first person I heard explain how massage works. She explained about the nervous system and how nerves went to the skin. She explained how mechanoreceptors at nerve endings in or below the skin sensed heat, cold, vibration, pressure, and that when we touched the skin with massage, our stimulation of these mechanoreceptors sent signals to the brain. The brain took in this information and decided how to respond to it. If the brain liked our touch, it would relax the body. It might dilate blood vessels, slow the breathing, relax muscles. If it did not like our touch, it might contract the muscles and constrict blood vessels. It was important, she told us, to create a positive experience for the nervous system rather than to create pain.

Meanwhile, I learned about Hilton’s Law in NMT seminars. Hilton observed that a nerve that innervates a joint usually also innervates the muscles around the joint and the skin lying over the muscles of that joint. The significance of this to us was that the application of heat or ice to the skin was said to have an effect on deeper muscle tissues through the nerves in the skin being stimulated by the heat or the cold. Although the heat or cold may may create the sensation that it penetrates deep into the muscles, the sensation of depth is an illusion. Later this would help me understand how what we think we feel may not be an accurate reflection of what is actually happening and might also provide an explanation for the sensation of affecting deep muscles when it just seemed implausible.

About a year and a half ago I began meeting some manual pain therapists who rejected the notion that pushing into irritated  tissue was the best way to get rid of musculoskeletal pain. They challenged the assumption that we can “touch” muscles. They pointed out the obvious: we can only touch the skin. Well, yes, I thought, but we can push through the skin into the muscle tissue below it, can’t we? They also pointed out something that took me back to what my teacher had said long ago about how massage works: when we touch our clients with massage or any other manual therapy, it is through stimulating mechanoreceptors in the skin that change is created via the brain.

 

A change in thinking



It took some time for these ideas to sink in but slowly I began to see that not only did they make sense, but it explained the questions that had been in the back of my mind for many years. Perhaps when someone pressed their elbow into my hip, the sensation of penetrating deep enough to affect this tiny portion of piriformis muscle lying underneath several inches of fat padding was actually a sensory illusion. How could pressure  diffused by skin and several inches of padding destroy endplates deep below? Maybe it wasn’t the pressure to muscle fibers themselves, maybe it was pressure to the mechanoreceptors in the skin.

This could also explain why pushing on what we thought of as the edge of a muscle, rather than smack in the middle of its belly, might have an effect. It would also account for why sometimes one didn’t need all that much pressure to calm some trigger points.

When I thought about how my touch stimulated mechanoreceptors in the skin, things made more sense. Most mechanoreceptors are in or just below the skin. There are some in deeper tissues but in order for us to “reach” those deeper receptors we still have to push into the skin where we are stimulating many more receptors. There’s no way to get past them without stimulating them. 

Slowly, my thinking has changed. I’ve come to doubt that when we push into the body that we are doing what we think we are doing. I know it feels as if we are pushing into muscle and that it feels like pressure on muscle tissue creates the change, but I doubt it. I suspect the sensation is probably an illusion.

 

Our brain is good at creating illusions



Our brain can easily create very convincing illusions. The rubber hand experiment has shown that people can easily begin to feel as if a rubber hand is their own hand, even while knowing it is not.

 

 

Recently, I had an experience of an illusion that felt very, very real. I was in a seminar and we were practicing a technique. I was lying on a table, face down, with my arm hanging off the table. A therapist was applying very gentle traction to the skin of my arm and holding it for several minutes. My arm was stationary and I could feel my hand lightly touching her knee, which gave me a point of reference. About a minute into this practice, I began to have the sensation that the therapist was moving my arm in a spiraling motion and that my arm was bobbing as if it were floating on a wave. I knew that, in fact, my arm was stationary and I could feel my hand continued to touch the therapist’s knee, yet this sensory hallucination persisted and felt very real. It was a pleasant sensation and I  enjoyed watching my brain play tricks on me.

As massage therapists, both we and our clients have sensory experiences for which we have explanations. Our explanations may or may not be accurate. As we learn more about how the body actually works, we adapt our thinking and our explanations to what we learn. Our methods may achieve particular results but the way in which those results come about may not happen the way we think they do. When we understand how the body works, technique rises out of that understanding.

 

Are we really doing what we think we are doing?



I have come to doubt that we touch muscles in the way that we think we do or that pressing into muscles does what we think it does. However, this has not upset me. Thinking about the nervous system, about the skin, and about how our contact with our client’s skin speaks directly to their brain has opened up an entirely new world to me. I heard it first from Deane Juhan in his book Job’s Body: “The skin is the surface of the brain.” I’m starting to understand what that means.

 

Submitted byGilad (not verified)on Mon, 05/14/2012 - 5:51pm

Hi Alice,

First, Its very interesting blog you have- thank you, I really enjoy reading it !

Secondly, I have a question (sorry for my English):

According to the article: "Pushing Into Muscle: Are We Really Doing what we think we're doing" you published, do you still think there are cases where deep tissue massage is better than superficial massage? Is massage has to be accurate and we should know the muscles' origin and insertion now that we know that the nervous system is the "main player" here...

Thank you

Gilad

Submitted byAliceon Mon, 05/14/2012 - 6:54pm

In reply to by Gilad (not verified)

Gilad,

Thanks for your comment! Your English is fine.

Do we need to know origins and insertions? I think that as massage therapists we should have a good knowledge of anatomy, including the anatomy of the muscles. However, my own training barely covered the nervous system and the major nerves. I am now going back and learning more about the smaller peripheral nerves and, in particular, the cutaneous nerves. I think this could be useful. In addition, I've begun learning about pain research and brain research and this takes us far beyond simple anatomy.

Do we need to be precise? I don't know. I used to think so but now I'm finding that when I work more more gently and with the skin that I don't need to be quite as precise as to location. This could be because the skin is rich with mechanorecptors and some of them have very large fields.

Is there still a place for deep tissue massage? That's a question I'm still asking myself. I will say this: I don't think that there is ever a place for hurting clients. The idea that massage must be painful to be therapeutic is an idea that should be abandoned. However, I acknowledge that sometimes people crave an intensity of experience. Is this always a bad thing? I'm not sure.

There is a forum called SomaSimple where manual pain therapists discuss neuroscience and manual therapy. Currently there is a discussion exploring the question, "Is less always more?" You may have to sign up as a member to read the discussion; some are public and some are not. I don't have a definitive answer to the question. What I will say is this: I'm learning that more pressure is not always necessary and that I don't always have to push hard to alleviate pain. Is this always the answer? I don't know for sure.

I encourage you to check out the SomaSimple discussion, learn more about the brain and the nervous system and its role in the experience of pain, experiment yourself with your own clients, and come to your own conclusions. Learn, keep an open mind, observe . . . that's all we can do.

Thanks again!

Alice

 

Submitted byKatie (not verified)on Tue, 05/15/2012 - 3:23pm

Thank you for this! Like you I have begun to suspect that therapeutic effects of muscularly-oriented massage are due (primarily at least) to a neurological response, rather than a direct, local tissue response.

But my question for you is this -- does it necessarily follow that the entire response is driven by nerve endings in the skin? What about proprioceptors and stretch receptors in the muscles (and tendons) themselves? Surely we can move muscle around some, lift it, spread it, deform it, even if we can't literally "touch" its mechanoreceptors.

Submitted byAliceon Tue, 05/15/2012 - 6:58pm

In reply to by Katie (not verified)

Katie, that's an excellent question and I cannot give a definitive answer. However, I would ask you to think about this: we cannot strip off the skin and directly touch the muscles or tendons themselves or their mechanoreceptors. We can only "touch" them indirectly through skin.

The skin is rich with mechanoreceptors. There are mechanoreceptors in muscle, fascia, joints, tendons, but far fewer. Just to make up some numbers, let's say there are 10 receptors in the skin for each receptor in the musculo-tendinous-fascial tissue below. If we push into the skin enough to possibly affect mechanoreceptors below, we've still stimulated ten times the number of them in the skin and, because of pushing through skin and adipose tissue and fascia, the amount of pressure delivered to those mechanoreceptors will be far less than those delivered to the skin. How do we separate out the effects of stimulating receptors in the skin from the stimulating far fewer receptors below with far less pressure? We can't. It seems the amount of stimulation given to the receptors to the skin is most likely to have a far greater impact.

Think of this: the sensory nerves go mostly to the skin. What goes to muscles are mostly motor nerves, which do not "feel," they create movement. Proprioceptors tell us where we are in space. Stretch receptors contract the muscle to stop it from going too far when they are stimulated. I'm not sure how either of them might come into play during massage but, as with other mechanoreceptors, you still have to get past all those receptors in the skin before you ever get to them. So, how could you tease out their role and why would we want to think they play a greater role than all those sensory nerves in the skin?

I haven't given up the thought of applying pressure within the client's comfort level. However, I think we've overlooked the importance of the nervous system in creating change and that we've overlooked that what we are really touching and pressing on is mostly skin. We can push some muscle fibers around below but watch your hands and think about it: which is being deformed more, the muscle or the skin? And which has more sensory nerve endings? Watch your hands and think about it.

It's easy to see why we ignore the skin. The anatomy books show us the body with the skin stripped away. In gross anatomy class, we quickly stipped the skin away to get at the muscles below. It's easy to ignore the skin, to look right past what is in front of our eyes and what is actually in our hands.

For those of us who have assumed that we have to press hard into the body to make a difference, the idea that we can have a significant effect working on the skin is, at first, strange. However, "skin deep" may be "deeper" than we thought. After all, the skin is connected directly to the brain via the nerves. I don't know about you, but going to the source is about as "deep" as one can get and that realization amazes me.


What do you think?

Hi again,

I'm not sure how one would experimentally tease out the different effects on skin vs. underlying structures. But I'm not willing to rule out the idea that we can influence those deeper mechanoreceptors in a therapeutic way.

The nervous system is quite good at down-regulating 'normal' input from the skin -- why you don't actively feel your clothes all day, or the chair you're on, until you think about them -- so it seems plausible that in the context of massage the CNS might manage to attend to the deeper stimulus and ignore or downplay the stimulation of the skin. (One reason for starting in slowly / "warming" the tissues?)

It's not strictly a numbers game, and just because there are MORE receptors in the skin, doesn't mean the nervous system will necessarily attach significance to that input. It might be more interested in the other, more notable (maybe novel or painful) sensations that are going on at deeper levels. Perception is one of those complex socio-bio-chemical-neuro-cultural-contextual-psycho-emotional-etc. things. ; )

Think about it this way. The density of nerve endings in the skin of the hand is about 100 times of that in the back. But if you've got a back ache, and you rub your (somewhat hypersensitized) lower back, I will bet you're going to notice that sensation in your back more than the sensation in your fingers. Your CNS just cares more about what's going on with the back in that context.

Anyway, just thinking out loud. I certainly do agree with you that the significance of the skin and of the nervous system generally are not often given their due!

Katie, you make some interesting observations and raise very good questions.

I agree. I don't rule out the possibility that we might affect deeper receptors. I don't know. What I question is our assumption that our effects come primarily through deforming receptors in deeper tissue. We almost completely overlook the skin, the fact that most sensory nerve endings are in the skin, and I think it's time for us to start considering that.

Why do we stop feeling our clothes? Light touch is sensed by rapid adapting mechanoreceptors that stop reacting to our clothing very quickly. They are like a momentary switch that is "on" for a moment and then turns off until there is new, external stimulus. Other slow adapting receptors continue responding to stimulus, like a switch that is turned on and stays on as long as the stimulus is present.

You correctly point out that the concentration of sensory nerve ending varies from one part of the body to another. Additionally, different mechanoreceptors have different "fields." Some have large fields, some have small fields. So, for instance, if someone pokes you with a small probe or needle on your hand, you are likely to be able to identify exactly where it is because the sensors that respond to this stimulus are numerous on your hand, even though their fields may be small. However, you may have more difficulty correctly identifying the exact location if you are poked on your back or may not even feel a needle because there are fewer receptors that respond to this type of stimulation and their field is small, so you may "miss" their field. However,  there are other receptors that have a broader field and they will respond to stimulus from a larger area. Rufini corpuscles are slow adapting mechanoreceptors with broad fields. When you put a stretch on the skin, they will continue responding until the stretch is discontinued.

I appreciate your taking the time to share your thoughts and questions. It is through this process of inquiry that we learn. There is a lot still to be learned about the brain, the nervous system, the mechanoreceptors, how we adapt. I am just beginning to explore this myself and, like you, have many questions. The more I learn, the more questions I have! I welcome yours and your thought and appreciate your interest in being involved in the learning process.

Great post. I took neurology, peripheral injury, spine injury courses; training in spine rehab clinic; and finally trained in McMaster university's neurological oriented acupuncture program. Anatomy, clinical experience, and Neurology are the foundation for understanding the pain and musculoskeletal system.
not only RN and massage therapist, lot of physiotherapists and chiropractors also need training and learning to improve their knowledge.

This article really makes you think. Especially after practicing what we've known for so many years. It really makes you want to think out of the box.

 Hello! Thanks for your comment.

I just checked the links myself and I'm not having any problem. However, I did notice two things: one is that it is necessary to scroll down the page to find the section on the Gate Theory. If you found a chart with different mechanoreceptors, that's the right page. I'll make a note so readers won't be confused. The second thing that I realized is that I have a link in the text to the video of the Rubber Hand Illusion and also the video embedded in the article, which is obviously redundant. So I'll fix that. I'm not sure why I did that but I am not very experienced at this website stuff and was even less so then! So I'm a little clumsy now and then. I do appreciate you letting me know. I'll ask someone else to log onto this article and see if they are having the same trouble.