The Deep Front Line (DFL, from Thomas Meyers Anatomy Trains) is one of our most fundamental tracks of soft tissue. It is the soft tissue equivalent and partner of our skeleton (especially the axial) and is what most fundamentally holds the core of our structure together when it comes to musculature and soft tissue. To explain its role to my patients I tell them to think of a bridge. The concrete or steel of the bridge is your skeleton/spine (primarily axial) while the tissues of the deep front line are like the tension cables. Together their compression and tension hold together as the foundation of our structure with excellent integrity, if everything is doing its job. As long as there is no break or other structural problem with the skeleton (that concrete/steel part of the bridge) then we don’t have to worry about that. The majority of the problem comes in when there is problems in regulating tension in the soft tissues of the deep front line. All of you reading this know it’s not a matter of isolated or simple chronic tightness or ‘over use’ that causes tension disparities, nor is it because the muscles are ‘weak’ so we won’t even cover that aspect here (it seems half my articles are just explaining the premise of neuromuscular control theory).

Most of the 'Deep Front Line' which is commonly an instrumental element of TMJ dysfunctions.

Most of the ‘Deep Front Line.’

So what problems do happen with the DFL tension? Simply stated one length of the deep front line either gets too tight or too loose for the overall DFL to hold the tension it needs for dynamic structural integrity. When one length tightens too much…another has to slacken. When one slackens, another has to tighten. Any of you who do neuromuscular work and are familiar with anatomy trains can probably without hesitation tell me what 75% of someone’s deep front is up to (facilitation or inhibition) without even looking; and you probably have some notion for what’s causing what. This is because while individual circumstances and variables will change exactly what’s going on, the overall approach that the MCC takes to keep the structure safe is generally the same: compress and limit range of motion (there are some joints and injuries where this is not the case, such as ankle injuries). Anything that can compress is usually used for this function, and anything that will decompress is usually at least down-regulated if not inhibited.

The overall effect commonly looks like an undulation of facilitated, inhibited, facilitated, inhibited, etc. though not always. For example I most typically find the toe flexors and or post tib working for most if not all of the adductors. The pelvic floor is either facilitated for itself (commonly posterior to anterior but it can be all or nothing as well, especially after pregnancy/genital surgeries; episiotomies are common culprits) or for part of the core above. The iliacus is commonly facilitated for the psoas, though honestly I don’t tend to consider the psoas and iliacus as part of the deep line structure in this way, but I’ll leave that opinion for another article. The TVA, RA and multifidus is typically inhibited, with the TVA having the hardest job working (95% of the time or more it doesn’t; if you find one functioning, DON’T BELIEVE IT. Mess with things until it fails. If they’re on your table with a complaint, I don’t believe their TVA. An eccentrically loaded diaphragm is probably making it look like a pass.) followed by the RA and then the multifidi closely behind. The pelvic floor may be working for one of the aforementioned 3 primary core muscles, though the next step in the chain is the diaphragm which because it is attached to a balloon it’s an amazing central hub of facilitation. Commonly it will hold tension, even if only eccentrically (check my article on eccentric contractions causing false positives) to give the MCC enough sense of tension to allow things to function, including the TVA.

The deep front line continues up along the spine and throughout the thoracic cage including wrapping around the lungs and other organs. If your patient has pleurisy, see if clearing the deep front line helps as the condition is generally considered idiopathic but my money is on some form of severe deep front line dysfunction. As we go proximal we get into the deep neck flexors, which are commonly inhibited by a whole mess of things (extensors, especially suboccipitals, 1-2 of the scalenes, and or a levator), then into the floor of the mouth, the tongue, the masseter, and the temporalis. Unsurprisingly, this last group of structures tend to be highly facilitated. With the jaws wide range of motion and extreme strength, let alone common use, it is a shoe in for holding tension at the top of the chain so is very typically facilitated for large stretches of the core in the DFL as well as the neck, causing TMJ ‘syndrome’ frequently (even if they aren’t aware, see how evenly their jaw opens at the TMJ) and occasionally with attached tinnitus, let alone tension headaches around the temporalis.

So to recap and add a bit: we often see the deep posterior calve compartment working for the adductors, as well as the psoas, sometimes more (I’ve seen iliacus, TVA, RA, etc.). The pelvic floor, diaphragm and jaw commonly are facilitated for any of the three main core muscles; the TVA, RA, and multifidi/erectors (sometimes one to one, sometimes one to all). The neck flexors can be do the jaw or something else in the deep front line but usually I find that a local relationship to the neck/cervical vertebrae as part of a cervical compression strategy (more in my article on c2 displacement concerning cervical/axial compression strategies).

The thing to remember is that this is not a facilitation/inhibition relationship of ACTION, but one of tension. While one adductor may inhibit another via reciprocal inhibition as a functional antagonist, and a gastroc head may cause plantar flexon when there is no extension of the hip for ambulation, this set of relationships is most purely one of creating adequate structural tension around a strategy of compression. This means that while the pelvic floor, diaphragm and TMJ musculature are facilitated, releasing them does not necessarily fix the problem. Typically these structures tighten because something else fails and tension is required. As I tell my patients; if you take a week off sick and come back to find your co-worker has been doing your job, is that their fault? The work needed to be done, so they did it, don’t blame them. But if you can’t get your work done because of a mugger? Yeah, that’s the guy to take care of.

As always I urge people to find the actual culprit; releasing a facilitated diaphragm is no better than our previous paradigm of stretching a muscle because it’s tight. You must ask and find out why! I do not release these muscles very frequently because they are victims being forced to work too hard in most instances. Sometimes a local trauma will change the situation but most of the time it is simply a global stability strategy and you need to find the source. I may treat some symptomatically (but never the diaphragm) at these levels, but you aren’t treating the source unless you have reason to know it’s the source.

This brings us to finding the original cause, which generally goes out of the scope of this article but we’ll give you a direction. 90%+ of what I treat is scars, concussions, broken bones and joint injuries, or they are being referred out to deal with limbic trauma (see my article on limbic/MCC function and their interplay in rehab work). There are of course other injuries, but these cover the main sources of ‘original causes’ which are driving the body to create a global compensation strategy in the first place, which again is marked by axial compression and is likely the cause of your deep front line dysfunction.

So let’s take an example: Patient A presents with chronic headaches, neck tightness, and low back pain. Upon initial testing you find the flexor hallucis longus working for the majority of the adductors and the psoas, the masseter working for the neck flexors and diaphragm working for the TVA. A pretty typical pattern, but when we get into the history we find that this patient had a vaginal tear (or episiotomy) during birthing and that she has also had urine urgency and poor sense of bladder fullness (when she has to go, she has to go immediately, and probably leaks very easily) as well as frequent constipation. This kind of injury is a severe insult to the deep front line and given its location on not just the deep front line, but the anterior core and on the genitals themselves the body frequently feels highly unstable and reacts globally.

Following the likely chain of compensations from her history and symptoms, we can see that her anterior pelvic floor is inhibited (she also reports not being able to feel a kegel, or if she does she can tell it is very weak and minimal; she may even feel pain during sex which may also be from a facilitated pelvic floor) and while it may be from another cause (non-neuromuscular) her posterior pelvic floor is likely to be facilitated for it to hold appropriate distal tension. By doing spot releases or an anti-kegel followed by a kegel you may or may not see improvements in neural connection to the anterior pelvic floor, but this isn’t the cause anyway so I am not concerned.

Moving on and up this instability leads to axial compression, likely including one hip, SI joint and an elevated shoulder on the same side (typically the side that is most unstable) which is capped (again commonly but not always) with an inhibited levator, resulting either in defensive tightness pulling the C2 and other vertebrae out of place or the other levator/scalenes which are facilitated are responsible for the subluxation. The C2 deviation or the SI jam ‘directly’ inhibit the TVA and cause even more dysfunction. A non-functioning TVA, faciliatory diaphragm, and cervical compressing secondary respirators all throw out the breathing patterns and seal the global compensation pattern.

The increased tension on the TMJ musculature and the compressing elements of the neck cause a lot of global tension to be routed through them, resulting in neck tightness and chronic headaches. A jammed SI and non-functioning TVA would be enough by itself to cause low back pain, but in all reality we would also have no psoas function and probably only one capable QL.

Going back to the likely original cause in this case, we instruct the patient to assist us in testing the pelvic floor scar and then releasing it. If this is the original cause we expect it to be, the SI should no longer be very causally involved, giving us a big jump in hip and lumbar spine stabilizer function (TVA, psoas, QL) and release the structurally mandated tension on the TMJ musculature. The pelvic floor itself may or may not immediately respond but I generally find unless there is a more severe injury at play, the patient should be able to feel a difference in her kegel (but again, not always right away!).

She may need symptomatic approaches for a time in addition, so other than the fundamental homework that would be scar release to kegels (yes, we on rare occasions assign kegels!), releasing the SI jam to a severely inhibited TVA via dying bug and release of one levator to another or suboccipitals to the deep neck flexors would be an appropriate approach to treatment.

Another worthy mention is that if someone has symptoms such as these; especially something like TMJ, there may be nothing you can do to permanently resolve it if they are a persistent gym chewer. Loading up extra pressure on the masseter will strongly reinforce the compensation despite your best homework releases in many cases, and part of the thing to realize is that it isn’t just additional time chewing. Because of the thickly ‘chewey’ nature of gum we tend to try to “smash the shit out of it,” as I put it to my patients (they laugh and then realize it’s really quite true). They really need to ditch the gum or their neck/head/jaw issues are likely there to stay forever.

Similarly, breathing patterns MUST be addressed to get the core (especially the TVA) working again and the diaphragm/secondary respirators regulated. Simple diaphragmatic breathing (having them hold their hands on, but don’t push, right below the belly button while supine and practice pushing their hands out with their low stomach during their inhale; starting and contributing the vast majority of their breathing volume with their abdomen, only having chest involvement near the end.

So there is a general approach and info to the role of the deep front line; the soft tissue foundation of our structure (just for more examples; the supporting rope for a mast, or the lines for a tent). Normalizing someone’s deep front line is one of the most profound things you can do for them and if you successfully clear it (not that you won’t have to venture out of the deep front line at times to treat it) their symptoms won’t likely stay gone for long. The next step would be making sure their rotational lines work as all real human movement is a mixture of rotation and counter rotation; when these don’t work properly then force must be transferred into other planes and inappropriate structures causing wear and a load of issues, but that’s for another day.

Filed under: The Practitioners Corner

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