Course Notes: PRI Postural Visual Integration: The 2nd Viewing

Would You Look at That

It was a little over a year ago that I took PRI vision and was blown away. A little bit after that, I went through the PRIME program to become an alternating and reciprocal warrior.

I had learned so much about what they do in PRI vision that I was feeling somewhat okay with implementation.

Then my friends told me about the updates they made in this course.

I signed up as quickly as possibly, and am glad I did. This course has reached a near-perfect flow and the challenging material is much more digestible.

Don’t expect to know the what’s and how’s of Ron and Heidi’s operation. And realistically, you probably don’t need to.

Your job as a clinician is to take advantage of what the visual system can do, implement that into a movement program, and refer out as needed. This blog will try to explain the connection between these two systems.

If you want more of the nitty-gritty programming, I strongly recommend reading my first round with this course. Otherwise, you might be a little lost.

Let’s do it.


I See…

Vision is much more than just the ability to see clearly.

Although vision makes up 70% of the brain’s sensory information, only a portion deals with the picture perceived.

Visual input affects sensorimotor systems via connections to the superior colliculus. This brain area receives only peripheral vision. Thus, if minimal peripheral visual input is perceived, all sensorimotor systems must accommodate in some fashion.

That includes the movement system.

Due to parietal lobe asymmetry, there is a natural disadvantage to perceiving left space. Both lobes collect information from the right visual field, whereas the right parietal lobe is the only brain structure that maps left periphery.


Combining the above two facts, it seems evident that a rightward visual bias can potentially influence how we move.

If peripheral space is decreased, the body will increase verticality to make up the difference. Vertical space increases as horizontal space decreases.

The need to extend becomes present as peripheral input is dropped off.



Eye Walking


“Gait is not owned by feet. It’s owned by processes of perception of all senses.” ~ Ron Hruska


Gait is a prime example of how the above paragraphs functionally work.

The gait cycle follows this typical progression:


Heel strike → midstance → push-off → early swing → late swing

This explains what occurs at the lower extremities quite simply, but rarely does one talk about what occurs at the thorax or visual system. These areas are also active in the gait cycle.

Gait is not just about legs moving, but systems locomoting.

Let’s take a more in-depth look at gait:


Lower ExtremityHeel strikeMid-stancePush-off
ThoraxWeight acceptanceTrunk glidePush to balance assist
VisionPeripheral contactPeripheral Optic flowPeripheral propulsion


Peripheral contact…

 is simultaneous awareness of the floor and peripheral vision. Lacking peripheral vision will increase difficulty finding floor and reaching out into space with the stance side arm.

Limbs will not interact with unperceived space.

This process can be improved by perceiving peripheral objects without directly looking at them, judging distances between objects, and progressing from enclosed environments (e.g. hallways) to open environments.


“Your heel is a strike bone. If it doesn’t your visual system will strike hard.”


Peripheral optic flow…

is sensing objects moving backward as the body progresses forward. This sensory input provides space for a body to propel into, and is needed for centering during midstance (more on that later).

To enhance this quality, one can notice objects in periphery moving backward, tap objects with the left hand, and tap ground with the right foot.

Peripheral propulsion…

is noticing the body moving forward through space via alternating peripheral awareness. In order to notice this change, one must become aware of arm swing occurrence.

Recognizing arm swing is what allows the contralateral lower extremity to swing forward and “catch” the advancing body weight. Lacking this quality may be why many individuals have poor arm swing during the gait cycle.


“Feet don’t swing unless arms swing” ~ Ron Hruska


So to summarize this progression, one must recognize peripheral space to contact ground (peripheral contact), ands notice objects in the periphery passing by (peripheral optic flow) as the body progresses forwardly via limb reaching (peripheral propulsion).

If these pieces are not present in gait, then forward progression may not occur with integrity. Namely, because there is no perceived space to move through nor is there ground to contact. Lacking these inputs creates increased verticality (i.e. extension) in order to prevent falling, which is ultimately what makes the PRI patterns (dis)advantageous.



In order to effectively master midstance, one must be able to center.

Centering is the ability to balance ascending (foot and ground support) input while perceiving appropriate visual input in a lateralized, upright position.

If one cannot center, the visual system can possibly enhance focus on a close or far object to stabilize the body upright. This enhanced focus will likely promote system extension by dropping off peripheral vision. As we learned above, dropping off peripheral will impact one’s ability to manage the floor and reach with extremities.

Here is what it looks like:

Having the ability to center is what connects space, ground, and body for effective ambulation.


An Optometrist’s Role 

An optometrist elicits postural change by manipulating space with lenses. This orthotic works by:

  • Changing where the extraocular muscles are directed.
  • Altering visual information received both consciously and subconsciously.
  • Affecting clarity.

These changes can remove undesired references or enhance desirable ones; especially if other sensory inputs have failed.

Lenses alone will not make a favorable change; one must implement a movement-based approach to use the references a lens may allow access to.

Lenses are akin to manual therapy; creating a window for movement to drive neuroplastic change.

Realize that regular optometrists won’t be able to do the things that one who is PRI-trained will. A traditional or even neuro-optometrist is not looking at vision as an extension of a triplanar system.

That said, that doesn’t mean that a traditional neuro-optometrist isn’t essential to have. Sometimes keeping the eyes working together (binocular vision) without being overcorrected can do wonders.

Some suggestions for your local OD could be asking for power less than 20/20; or putting someone in distance-only glasses over bifocals or progressives. These lens types are not inherently bad, but some individuals may not use them properly; especially if there is no clear delineation between lenses.

Another suggestion may be to try the spherical equivalent, which basically eliminates the patient’s astigmatism correction.

Here are a few examples of people who you may want to send to an optometrist:

  • People who can’t drive at night due to vision – these folks use the visual system to stabilize.
  • People who have some type of visual impairment, cataracts as an example.
  • People who are nearsighted. These individuals may not pay attention to distant or ambient information because it’s imperceptible.
  • Monovision – get them out of this!

A lot of optometrists may use vision therapy to aid in the process, and this modality can be extremely beneficial. However, it is imperative that the neck is neutral prior to going this route. Teaching visual skills on a locked-up neck can keep the neck patterned.


Visual Coaching

Ron and Heidi provided some excellent coaching tips that I thought needed to be shared.


On references centers…

Clients attending to and feeling reference centers is essential, but they can’t overfocus on trying to feel only one reference. This may lead to increased system focus, which is associated with extension.

On speed…

Speed is not the name of the game during PRI vision programming, as greater pushes in speed lead to greater extension demands.


On Neurodevelopment…

For those into using neurodevelopmental techniques, reaching capability precedes creeping and crawling. The reach must be taught first before the latter skills are applied.

If you don’t have a neutral thorax, you lack the ability to crawl.


Infamous Ron Quotes

  • “I don’t know if there is such a thing as running anymore.”
  • “I see biceps, lats, and pecs, oh my.”
  • “[Running] is the best horror movie you can go to.”
  • “In every shoe store there should be an optometrist.”
  • “I have glasses on ankles and I have shoes on eyes.”
  • “Animated hands are alive people.”
  • “Hips are the glue between floor and space.”
  • “Your hand is your communicator of your body.”
  • “Chairs ruin squats.”
  • “I want saccadic ankles.”
  • “Pronation is periphery.”
  • “Gait is probably better owned by your visual system than the floor.”
  • “We see people who push off and want to get to the moon.”
  • “Feet don’t swing unless arms swing.”
  • “Balance and cognition are the same thing.”


Very Wise Heidi Quotes 

  • “Neck, vision, and vestibular are all locked together.”
  • “My job is not to make you see clearly.”
  • “Sometimes pain is a good reason to give up convenience.”
  • “Just because you see doesn’t mean you use it.”
  • “People tell eyes what to look for.”
  • “You won’t reach if you don’t see space to reach into.”
  • “You won’t change if you see the world as you do.”
  • “When patients pick up speed during a program, you are done.”


  1. Maybe I left lateralized my hair to make up for my right torsion! Loved reading your course notes, Zac. You make complex neurological/biomechanical descriptions easy to digest for the new kids on the block like myself.

  2. Zac, I always look forward to your blog posts. I love the search for broader perspectives and integration of multiple “disciplines” into our understanding of movement and pain. Keep up the good work!

  3. Hey Zac. Where are you? That is amazing blog. I hope so that you will make comeback as Jay-Z. High V bro

  4. Zac! I just want to reach out and say THANK YOU for putting your course notes online. I am a patient with Post Concussion Syndrome. It’s a long slow journey back to health! Reading your blog has helped me heal myself. THANK YOU!!

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