Postural Visual Integration--Course Review

I was fortunate enough to have attended the first "Postural Visual Integration" course last year that Ron Hruska, MPA, PT and Heidi Wise, OD, FCOVD put on and it really opened my eyes to the complexity that is our visual system and the influence it has on our structure, function and decision making processes.  While there have been some adjustments to this already excellent program since that time, I felt it would be helpful for others to be able to see how the Postural Restoration Institute and PRI Vision discuss the influence our visual system.

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POSTURAL VISUAL INTEGRATION

Ron Hruska, MPA, PT / Heidi Wise, OD, FCOVD

@ Point Performance Therapy, Bethesda, MD -- 2/28-3/1/15

“PRI Vision: Moving Beyond Sight”

“Vision writes spatial equations for our muscles to solve” – Myron Weinstein, OD

• Sight vs Vision
• Sight
• How clearly you see and the extent of your visual field
• If no disease or developmental issues, than each eye should have the ability to see 20/20 with correction if needed
• Each eye should have the ability to see the full visual field, i.e. no missing areas in side vision
• Sight is what is tested with standard optometric and ophthalmologic exams
• Your eyes are constantly moving , even when focusing or staring at something. It keeps us from going blind.  These movements are called ‘microsaccades’.
• There are blind spots in everyone’s vision and the brain basically fills in these blanks with what info it has received from the rest of the visual field.
• Vision
• “The deriving of meaning and the directing of action as a product of the processing of information triggered by a selected band of radiant energy.” – Robert Kraskin, OD
• The eyes are the only sensory organ that are a physical outgrowth of the neural tissue (the brain) that will ultimately process the sensory information.
• We are not born with visual skills, but rather the ability to develop them. Vision is the dominant sense in the brain.
• Over 70% of all sensory information in the brain is visual, and only a portion of that is related to the “picture” we see.
• Visual processing occurs in every area of the brain and integrates with information from all the other senses. It can “override” information from other senses and “overpower” other skill areas.
• “The peripheral visual system is responsible primarily for rapid detection and localization.” – Kimron Shapiro
• Some visual areas in the brain are asymmetrical. For example, the right parietal lobe contains a spatial map for both the right and left visual fields, while the left parietal lobe contains a lesser important spatial map for the right visual field only.
• Vision is involved with making movement decisions, cognition and even emotion.
• Vision is the most powerful cortical stabilizer we have.
• Muscles of the eyes are 300x stronger than they need to be for moving the eyes.
• The eyes, as appendages, need to move independent of the head and neck so they are not over-utilized for stabilization.
• Centering
• Centering is a PRI Vision concept that reflects the neurological ability to use appropriate visual perception, capitalize on ascending support, and balance in a lateralized upright position. It requires effective and efficient respiratory function from the diaphragm and pelvic floor through visual input that relaxes the upright organism to decompress the spine (flexion).  A desired respiration position can then be achieved as the need to accommodate (compensate) for stabilization with the visual and cervical systems is reduced.
• The visual process not only affects our ability to center, but in turn is affected by it as well. It’s a system—no one part exists in isolation.
• The Visual Phases of Gait
• In order to be able to sense forward motion you have be able to see things moving from front to back with respect to an individual’s body center, which requires balanced peripheral awareness.
• Looking at gait from a visual perspective:
• Ground = stance / space = swing
• Peripheral contact = heel strike
• Peripheral contact / heel strike requires:
• Good peripheral awareness.
• Good sensory ground impact from the calcaneus while the hip is extending from 30 degrees of hip flexion and requires toe clearance on the other side from anterior tibialis and toe extension co-activity.
• Association of cerebral and cerebellar behavior of its initiation
• Momentum memory/muscle memory of the tibia traveling forward at heel strike which starts the sequence.
• Forward progression begins at initial peripheral contact and if not in good control for acceleration, than control during further phases of the gait cycle is unattainable.
• Peripheral optic flow = mid-stance
• Ground decompression at mid-range of mid-stance requires appreciation of visual periphery, especially at distance, and as a result, is the most passive phase of gait.
• The brain’s visual sense of motion is called optic flow and is about 50% of the stance phase of gait. Momentum during mid-stance is dependent on the sense of things being seen to move back.
• Cortical appreciation of these factors allow one to stand erectly without compensatory knee hyperextension or leaning forward, back or to either side.
• This phase is reciprocal and alternating visual activity. Leaning or listing during this phase distorts sensory input.
• Peripheral propulsion = push-off/toe-off
• The more the visual cortex recognizes the forward swing of each arm and hand, the more the other LE has to come forward to “catch” the advancing body weight.
• Lack of recognition of the peripheral distal hand at forward arm swing results in:
• poor forefoot propulsion and relative lengthening of ipsilateral LE.
• hip falling forward and foot over-pronates during toe-off when resupination is supposed to occur.
• poor ability to get the leg behind you.
• Awareness of peripheral alternation enables the body to naturally shift to the other side at the end of the peripheral propulsion/toe-off phase.
• This is why frontal plane activity and control is so important.
• Space = swing
• Pick-up = early swing
• Reach = late swing
• Pelvis moving forward = swing is pulling you. Pelvis moves back = stance is pushing you.  Better to use the ground properly than space.
• Vision terms
• Myopia = nearsighted: Uncorrected vision better at near than far. Light rays focus in front of the retina.
• Increasing in the general population dramatically. National Eye Institute found that in 1972-1973 that about 25% of the US population (ages 12-54) were myopic vs 41.6% in 1999-2004.
• Hyperopia = farsighted: Uncorrected vision better at far than near.  Light rays focus behind retina.
• Overall, having some hyperopia is ideal.
• Astigmatism = scoliosis of the eyeball. Light rays focus in two different places at the same time.
• Presbyopia: Normal loss of flexibility of the crystalline lens associated with aging.
• Accommodation: Process of crystalline lens changing shape, and therefore optical power, to maintain a clear image or focus on an object as its distance varies. It acts like a reflex, but can also be consciously controlled.
• Many people are over-accommodated in an effort to continue to try and get as much clarity with sight as possible, decreasing peripheral awareness.
• Biggest difference between this and presbyopia is age.
• People start to drop off distance and over focus to see clear up close and lose their periphery.
• Ambient visual pathway:
• Processes info from the peripheral retina
• Most sensitive to high-contrast, moving targets
• Does contain info regarding spatial localization
• Not affected by clarity of an image
• Decreased left peripheral awareness in most people with more left eye emphasis for treatment
• Focal visual pathway:
• Processes info from central retina
• Most sensitive to color, slow motion or still targets
• Concerned with detail and clarity
• Decreased right focal awareness in most people with more right eye emphasis for treatment
• Convergence:
• Act of eyes simultaneously moving inwards towards each other relative to their starting position.
• Divergence
• PRI Vision Intervention
• Changes in the visual process are used to inhibit learned behavioral neuromuscular patterns and the related, inappropriate activity that limits reciprocal, human movement. It is either removing undesired references or enhancing awareness of desired ones.
• Changing the visual process changes the following processes:
• Proprioception
• Auditory
• Vestibular
• Musculoskeletal
• Autonomic
• PRI Vision Developmental Patterns
• Right frontal lateral neurologic space is ambient (transverse plane) or peripheral
• Left frontal neurologic space is focal (transverse)
• Right SCM is used to return the head after reading a sentence.
• The right lateral rectus and left medial rectus pulls the eyes to the right when we read as our heads are sidebent and rotated to the left.
• The left lateral rectus and right medial rectus are eccentrically oriented.
• Triplanar irregularities in extra ocular muscle (EOM) activity on the globe and the orbit result in torsional irregularities on the cornea resulting in astigmatism or ametropia.
• Our centering of our body in space requires anti-gravitational activity from our vestibular system that allows rotation around the occipital atlanto joint, the right global vertical axis, the right diaphragm central leaflet, the right acetabular femoral joint and the right inferior calcaneal surface. These are all axis’ where right and left rotation occurs around a vertically oriented axis which is the transverse plane of the body.
• Our right eye appears to be our “relationship to our surroundings” eye because of the way our orbits are positioned in the normal human pattern.
• Our peripheral vision tells us if we are moving or still, our surroundings are moving or still, or if both are moving or still. Poor balanced peripheral awareness can be a factor in motion sickness or dizziness.
• Our left eye appears to be our fixation eye because of the way our globes are positioned to adapt to the normal human pattern.
• Constricted peripheral awareness reduces the amount of visual information available which reduces or disrupts the available context, which can easily decrease the quality of performance and understanding.
• Most optometric evaluations:
• Are done in sitting and the body was not meant to be refracted in sitting.
• Assessments are done in the dark looking into a focal machine with the back in extension and in forward head posture.
• Corrections are for right and left eyes independent of each other and not how they work together.
• PRI Intervention Considerations:
• Contact lenses do not change space or dimension like glasses which can improve spatial awareness and depth. Contact lenses are for clarity.
• Essentials:
• Left periphery has to be maintained.
• Eyes, head and neck have to move independent.
• Have to own one phase before moving on to the other:
• Peripheral contact
• Balanced ground activity
• Peripheral optic flow
• Reciprocal and alternating
• Peripheral propulsion
• Ability to push and reach
• There are 3 Levels of dysfunction and 3 Phases of interventions
• Level 1’s are the most common presentation
• It is a spatial distortion issue
• Quotes from Ron and Heidi:
• “Our view of our surroundings is distorted. We want to create a new distortion.  We are looking for spatial, visual and perceptive variability.”
• “Your dominant cortical eye may not be the same eye which creates the best positioning for the space you’re in.”
• “If you don’t sense something moving, you’re not moving.”
• “The walls and people need to become the new floor.”
• “Disocclude to disreference and therefore disorient so they can get eyes on the walls to walk.”
• “Your neck is regulating your body—it is your 5th appendage"
• “The neck is not creating the problem. It is a messenger that tells you if you’re neutral.  It is reflexive to account for imbalance.”
• “When you lose periphery and peripheral distance, you lose the ground.”
• “Far to close is reciprocal, if you go back to far.”
• Convergence to the right amount of divergence, and back to convergence.
• To an optometrist:
• “Is there any power you can take away from that prescription?”
• “Can you give me the best balanced prescription between the two eyes as best as they are able to?”
• “Do you prescribe lenses to affect movement and balance?”