If ‘a muscle’ is wrong, then what’s right? Q&A

Read on as Tom answers a student’s question after viewing Tom’s webinar on fascia from YogaUOnline.

Dear Tom,

I recently viewed your work on Yoga U and I am having difficulty reconciling your work with that of my curriculum in physical therapy. I understand your concept of fascia as a system, with which I agree, and have tried to bring in the experience I had during the fresh tissue dissection January 2015 into the physical therapy program.

However when you’re speaking about their importance over our traditional idea of muscle, I’m unclear. From my understanding, when you are speaking about muscle you’re commenting on the aspects of “muscle” that are not connective tissue based, leaving just the contractile components of the myofilaments – actin and myosin, because even in that myofilaments we still have non contractile tissues that maintain structure. Further more, when dissolving a muscle of it’s contractile components you will get, as you have demonstrated a beautiful connective tissue matrix of envelopes that encompasses and endomysium, perimysium and epimysium.

On the traditional side, when speaking about muscle, the term encompasses the entire marriage of structures that lead to the physiological mechanism to produce torque — all of the contractile components pulling on the non contractile components within the epimysium, that is innervated at the various neuromuscular junction by specific nerves.

The difficulty for me is that on one hand, you speak to the segmentation of muscles from the traditional dissection process as inadequate and potentially wrong biomechanically, but on the other hand, you cannot separate contractile components of muscle tissue from their non contractile components because then we wouldn’t have the ability to create movement. It seems like both views are struggling with the same task: how you take an inherently interconnected organism and, for lack of a better term, dissect it down in such a way that is teachable, biomechanically relevant, and therapeutically sound for when systems are impaired.

For example: I understand and have used the superficial back line in success with understanding strain. However, when labeled the lifter, I hesitate, as the quadriceps are profoundly important in upright posture as a knee extensor. Of course in static standing they are likely off assuming one has full range.
I would be very interested to hear your thoughts on reconciling these two worlds as I believe they can and should support one another. And I would be particularly interested in seeing more on how the nervous system plays into this and what your thoughts are on peripheral nerve maps/myotomes do or do not correlate with the different lines.

Dear fellow somanaut,

A webinar is a difficult format, anatomical nomenclature is inadequate to describe interactions of whole systems, and then most of all there are my own communication shortcomings and ignorance.

Of course organized movement is impossible without active nerves, functioning muscle cells, and intact tensile connective tissues. They all work together seamlessly, and indeed never existed separately. There are many aspects to the structure of muscle cells – such as titin, such as the membranous adhesive molecules – that go beyond just myosin and actin – and I leave this to more microscopic eyes than my own.

I have argued that dissecting the body (and thus analyzing movement) in terms of an isolated muscle was an artifact of blade-based dissection. While this approach has yielded many helpful insights since Vesalius, it also leaves out others that got lost in the shuffle of the last 300 years. Two other approaches I would recommend – but are only beginning to be researched – would be 1) analysis of the moving body in terms of individual neuro-motor units (fascicles) rather than only via whole muscles, and 2) connecting kinetic chains through the myofascia such as the Anatomy Trains, though others propose different models, such as Philip Beach. And perhaps a third, systemic method of dipping the body in a bath of solvent to dissolve away all the cellular elements so we could look at the extra-cellular matrix is an organized whole – a picture not yet seem in modern anatomical texts, but pointed to by Guimberteau – and for the precise reason that it is the connective tissue that gets divided by the blade.

Specifically, we could point to the blade sliding between the muscles as destroying the intramuscular areolar fuzz which has been shown by Huijing et al to be force transmitting. The blade sliding between the muscles and the ligaments obscured the muscles’ role in making the ligamentous system useful at all angles of effort (van der Wal). And then of course there is the importance of the fascial system in attaching organs to the body wall (and adhesions that restrict their normal motions) and the movement of the nerves within their various levels of ensheathing connective tissues.

brachialplexusdissection
Any use of the scalpel – here showing the neuromuscular bundle of the brachial plexus and median nerve – exposes some aspects at the expense of others. Here you see the bundle clearly, but we had to cut its connections to the triceps and brachial to make this demonstration.

So if I gave the impression that thinking in terms of individual muscles is ‘wrong’, let me amend that to ‘limited’, and apologize for any rhetorical flourishes in the webinar – to which I do not have access at the moment.

As far as nicknaming the various lines – e.g. the Superficial Back Line as the ‘Lifter’ or the SFL as the ‘Protector’ – please do not confuse the Anatomy Trains map, which is a map of fascial fabric connections within the myofasciae, and not a map of function. If my nicknames bother you, leave them out, they are not important. Of course we use many muscles (actually, I would say many muscle fascicles / neuromotor units) to stand upright and to constantly adjust that stance in functional motion – almost every motion would involve contraction somewhere within almost every line. We don’t walk – and I have never claimed we do – by contracting the back line, then the front line, etc. The lines provide stability and communication along the nap of biological fabric, while we activate many units to corral the body into function. Thus the neural mapping you mention is by design quite different from the lines and one should not, IMHO, try to shoehorn them together into one system.

Except that somehow we do, every day, manage to get up and walk, with fabric, muscle, nerve, and bone all contributing their part.

Hope this helps,
Tom