Course Notes: PRI Cervical Revolution REMIX

Note: I made some errors on the first rendition of this blog that were corrected after speaking with Eric Oetter. Courtesy to him, Lori Thomsen, and Ron Hruska for cleaning up some concepts.

Four Months Later

When the Lori Thomsen says to come to Cervical Revolution, you kinda have to listen.

Especially when tempted with soufflé. Ooooooohhh Lawwwwd
Especially when tempted with soufflé. Ooooooohhh Lawwwwd

I was slightly hesitant to attend since I had taken this course back in January. I mean, it was only the 3rd course rendition. How much could have changed?

There's no going back Ron
There’s no going back Ron

 

Holy schnikes! It is simply amazing what four months of polishing can do. It was as though I attended a completely different course. Did I get it all figured out? No. But the clarity gained this weekend left me feeling a lot better about this very complex material.

This is a course that will only continue to get better with time; if you have a chance to attend please do.

Let’s now have a moment of clarity.

Itsyabloig
Itsyabloig

 

Biomechanics 101

The craniocervical region is the most mobile section of the vertebral column.

This mobility allows regional sensorimotor receptors to provide the brain accurate information on occipital position and movement.

The neck moves with particular biomechanics. Fryette’s laws suggest that the cervical spine produces ipsilateral spinal coupling in rotation and sidebending. The OA joint, on the other hand, couples contralaterally.

C2 is the regulator of cervical spine motion; much like the first rib regulates rib cage movement.

C2=1st rib = Nate Dogg (RIP)
C2 = 1st rib = Nate Dogg (RIP)

C2 is also important for the mandible, as it balances the cervical spine during mandibular opening. The reason this occurs is because the mandible and C2 are at the same fulcrum level.

images

 

Pathomechanics 201

Often triplanar motion will decrease amidst progressive respiratory demand or threat. These changes help promote neck stability while simultaneously increasing demand on the mandibular elevators, extraocular muscles, and vestibular system

If these changes occurs long enough, sensory issues may become prominent.

Stability can occur through increased sagittal plane activity in the upper cervical spine and cranium either one of two ways:

  • O on A via posterior cranial rotation
  • A on O via forward head posture

Both strategies attempt to flex the cranium, but both are undesirable if occurring underneath a lost cervical lordosis.

OA hyperflexion is often seen in those who sit in front of monitors for long periods of time. The visual system helps promote stability.

Aka actually sit in your freakin' chair!
Aka actually sit in your flippin’ chair!

OA Hyperextension is an attempt to create an airway. Cranial protrusion may be utilized as a way to open up the airway under stable conditions. This position passively raises the hyoid bone, which often depresses when one uses a mouth-breathing strategy. These individuals rely heavily on the dentition for craniocervical awareness.

Aka get a larger monitor
Aka get a larger monitor, and possibly a haircut.

Of course, these are not the only ways undesirable neck stability can occur.

You might have a stable neck if:

  • You have a narrow palate.
  • You have a cross bite.
  • You have a narrow airway.
Just think if Jeff Foxworthy were a dentist.
Jeff Foxworthy coming to a dental chair near you.

 

Patterned Mechanics 3037

 The TMCC is the foundational polyarticular muscle chain at the neck, with the right side generally more active than the left.

The normal RTMCC pattern presents with the following at the neck:

  • C2-C7 orientation in the transverse and frontal plane to the right, with compensatory rotation and sidebending to the left.
  • The OA joint is sidebent to the right and rotated left as a passive orientation.
Yep, that's you.
Yep, that’s you.

The RTMCC may be present in isolation or with various cranial strains.

A cranial strain may occur if the left SCM sidebends the OA left within the RTMCC pattern. This compensatory movement occurs to attempt to reduce OA rotation and upper cervical strain.

If you weren’t sleeping during the biomechanics section, you will notice that this goes against Fryette’s laws. In order for this compensatory strategy to occur, the right alar ligament and posterior capitis muscle must become lax. This movement does help reduce torsion and compression on the upper cervical segments, but may create a cranial lesion in the process.

This compensatory movement is a precursor to a left sidebending cranial lesion, and this lesion along with others are quite prominent.

According to a 2008 study by Timoshkin and Sandhouse, 72% of individuals have a cranium that is in a sidebend or torsion pattern; with left sidebend and right torsion being the most common.

Of those two cranial strains, the left sidebend will be the most common. Let’s dive into that pattern more.

Using whichever diving face you prefer.
Using whichever diving face you prefer.

 

Left sidebend (LSB)

The LSB lesion is named for the sphenoid’s greater wing position. In this case, the greater wing is high on the right and low on the left. The occiput matches this orientation.

Where these bones will differ occurs about a vertical axis; as the sphenoid externally rotates while the occiput internally rotates.

The mechanical change at the atlas drives this position. The sphenoid just goes along for the ride.

A prime example of this cranial strain would be the lovely Garey Busey.

Though his personality is a bit more right torsion
Though his personality is a bit more right torsion

Right Torsion (RT)

RT’s also have a low left greater wing of the sphenoid, but the big difference is at the sphenobasilar joint.

Since the RT is a progression from the LSB, the occiput will attempt to sidebend right to level occipital position.  Since the sphenoid stays in position, torsion through the sphenobasilar joint occurs.

This twist is driven by the sphenoid as means to create pseudo-facial symmetry via extension.

Lorimer Moseley is actually a perfect example of this type of cranial position, as many facial features are flipped from a LSB face.

For the sake of science, I hope he is not offended.
For the sake of science, I hope he is not offended.

 

This is a Test

The only way to truly determine which cranial strain one has is through imaging, but PRI testing can guide us down a treatment path.

Admittedly, the cervical tests are not the most reliable of the PRI bunch. To attempt to offset this limitation, we shall imply a test battery to determine position.

There are four essential tests in the TMCC algorithm:

  • Cervical extension: Checks cervical lordosis presence; goal is 30-35 degrees.

If limitations are present it is likely that SCM hyperactivity is reducing the normal lordotic curve.

I think of this test as the extension drop test of the cranium. It tells you if you are working with someone who is sagittally lax or not.

  • Cervical axial rotation: Checking C7-T1 rotation, which reflects C2 position. Looking for symmetry at about 30-35 degrees of movement. This test determines the TMCC pattern.

Limitations will be present due to the cervical spine’s compensatory rotation and sidebend to the left. Placing the patient supine on a table rotates the spine further to the left, which places a RTMCC patterned neck in an end-range position. Hence, normally left cervical axial rotation is limited. We would see bilateral limitations in a BTMCC.

When performing this test you want to make sure that you do not give the patient a lordosis, for this can create false negatives.

  • Midcervical sidebending: I think of this test as the great comparer between the cervical spine and the cranium. Looking for symmetry at about 30-35 degrees. This test gives you a frame of reference for our next test.

In the RTMCC pattern, this test is limited to the right secondary to an arthrokinematic block. If the cervical spine is rotated left on the table, the neck cannot sidebend to the right. That’s Fryette’s laws brah!

  • OA sidebending: This test looks at cranial position. Looking for 8-10 degrees bilaterally.

More than 10 degrees of sidebending would indicate alar ligamentous laxity.

A  RTMCC individual would have limited right OA sidebending due to a bony block. In someone with a LSB however, you would have limited L OA sidebending because the left SCM pulls the OA over to the left. A RT could present with just about anything, as pathology is quite prominent in these folks. 

Cranial Destraining

 RTMCC repositioning and retraining goes about the following progression:

Cervical spine → OA joint → Mandible

The neck is the top priority because its mobility maximizes cranial sensory activity.

Moreover, most cranial activities are integrated multi-joint movements. Spending time doing “basic” PRI sets the foundation for one to combine complex movements.

But sometimes that's what you gotta do
But sometimes that’s what you gotta do

Mandibular movement is often normalized by the time the neck is cleared. The reason TMJ mobility may be limited because of craniomandibular discord.

In the RTMCC pattern, the right lateral pterygoid works with the right anterior capitis and right SCM to deviate the temporal bone and mandible to the left whilst the occiput (and sphenoid) are “stuck” in the left sidebend position. In a neutral system, we would expect the occiput and sphenoid to move to the right during this cranial movement. This tonal issue could limit mandibular movement.

Thus, a neutral cranium often restores normal TMJ mechanics. If problems still arise, then mandibular re-education may be necessary.

Sometimes you need a Dentist

 

Must be LVI-trained.
Though not all appreciate occlusion.

Of the two common cranial strains, RTs will most likely need integration.

With normal occlusion, one side of teeth should touch while the other discludes. This alternation creates lateral shifting in both the mandible and the cranium.

The canine teeth act as guides for where the jaw ought to be in space. When canines touch during shifting, molar contact follows as the teeth drop into position. This action is called group function.

Teeth touching is kinda important.
Teeth touching is kinda important.

If group function cannot occur, it is likely that a dentist may need to be involved.

Splint therapy is generally recommended in these cases. More specifically, mandibular splints are the go-to (which I spoke about here and here).

Maxillary splints are generally the devil. These splints tend to increase tongue activity and mandibular clenching to hold the splint in. The one major case that may warrant a maxillary splint is the presence of tori.

Wolff's law at its finest.
Wolff’s law at its finest.

Even if not using PRI splints, there are four essential pieces needed from a dentist:

  1. Don’t lock the mouth into a position.
  2. Move head back and jaw forward with canines.
  3. Feel one side occlude while the other side discludes.
  4. Have group function and anterior guidance between incisors.

Note – anterior guidance is when the incisors touch the molars disclude

 

#Explainocclusion

 You might be wondering how I educate people about this stuff in a nonthreatening fashion. I got this neat little tidbit from the Ronimal:

“Periodontal ligaments are so sensitive that a hair will throw off your gait.” ~ Ron Hruska

Think about that statement the next time you get something stuck in your teeth. Drives you crazy right? If there is something undesirable going on with your teeth, you will know about it in some way. Some output will occur.

Yes, it's called a chiari malformation
Yes, it’s called a chiari malformation

Moreover, think about what occurs at the dentition when stressed. Do you clench? Reducing this muscle over activity by splint therapy introduces a salient stimulus that could reduce the stress response, if the craniocervical region is involved.

Hint: It usually is.

Infamous Ron Quotes

  • “Every single bunion and ACL patient is a TMD patient.”
  • “I love dentistry, but I don’t like dentistry, but I like dentistry.”
  • “You cannot treat a neck if a neck can’t treat itself.”
  • “We are a product of how we move our cranium.”
  • “A bra strap will really mess a tongue up.”
  • “The worst thing you can do to a patient is splint their neck.”
  • “We still have a lot of goniometric minds.”
  • “What good is the polyvagal theory if you don’t understand the neck.”
  • “Don Neumann is the best book for 1% of the population.”
  • “Treatment starts when you appreciate frontal plane.”
  • “How can you treat a TMJ if you can’t control the T?”
  • “The vehicle you drive is not the problem, it’s the path your on.”
  • “A twisted levator is an untwisted neck.”
  • “Hallelujah you have a pattern.”
  • “When you lose your left ab wall the head and neck will pick up the slack.”
  • “You can learn a lot about cognition and personality if you look at a neck.”
  • “You can’t feel CSF flow if you lack a cervical lordosis.”
  • “Make sense out of sense.”
  • “A neck that can’t move will produce a cant.”
  • “Crossbites, pulled bicuspids, and high arches scare me.”
  • “Sedentary lifestyle and screens demand we go straight.”
  • “The pattern is sugar that tastes pretty sweet.”
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