Neurophysiologic Reflexes of
postural Regulation
Laura Hanson, D.C., D.I.C.C.P., NDT
www.originaldevelopment.org
Posture Development
• Postural reflexes
• Milestones
• Locomotion
Environment
• Free style vs
restrained style
• Learning to roll and
sitting up requires
using the abdominal
muscles – the
beginning of posture
Sitting Posture
• Around 7 to 8 months
• Do not leave to sway
unsteadily
• Muscles of the
abdomen, back
Balancing Upright
• Muscles of the
abdomen
• Muscles of the
buttock
• Muscles of the
shoulders and upper
back
• Muscles holding the
feet in the correct
position
The Walking Child
Shoulder and
neck hold the
chest up and
chin in
Buttock muscles
help the lower
spine from
hollowing
Lower Abs pull in
by 5 years of age
The Feet in Good Balance
• The child’s weight is
on the balls of the feet
and the outer sides
• The toes point
forward and the inner
sides of the feet are
parallel with each
other
Muscular Imbalances
• Child’s weight falls on
the inner sides of his
feet
• Toes shift outward
• Long arch of the foot
flattens
• Poor balance
Entertaining baby holders teach the child to walk on the
inner parts of the feet with the legs spread apart and
maintains the baby in one posture for long periods of time
causing fatigue.
Use or Lose It!
Biomechanical Relationship
Compression:
push
Tension: Shear:
pull
slide
Torsion:
rotate or
twist
• Gravity and tone
create rhythm
• Gravity and rhythm
increase tone
• Tone, rhythm, and
gravity create
movement
Cognitive
System
Emotional
System
Movement
System
Reflexive Control
• Central generators neural networks that can
endogenously (i.e., without rhythmic sensory or
central input) produce rhythmic patterned
outputs“
• “Neural circuits that generate periodic motor
commands for rhythmic movements such as
locomotion.“
• CPGs have been shown to produce rhythmic
outputs resembling normal "rhythmic motor
pattern production" even in isolation from motor
and sensory feedback from limbs and other
muscle targets
Postural Reflexes
•
•
•
•
•
Visual Righting Reflexes
Labyrinthine Righting Reflexes
Neck Righting Reflexes
Body on Head Righting Reflexes
Body on Body Righting Reflexes
Gravity
Location of
Center of Gravity in Human
Body Shapes
Red X marks the Spot
• The human body
responds to this constant
force
• From the time the infant
lifts the head to mature
gait
• Gravity as the main
reference point
• Postural reflexes serves
as the neuromotor
impetus for this adaptive
response
Outcome
• Constant barrage of afferent input into the
NS, causing a hypersensitive state within
the neuronal receptor pool
• Pools are made largely from interneurons,
allowing sensory input to be conveyed to a
higher spinal and cortical centers
• Simultaneously providing input for spinal
reflexive control of various functions
Visual Input
• Pathway optic nerve,
optic chiasm, optic
tracts
• Projecting to 3
subcortical areas:
pretectum, superior
colliculus, lateral
geniculate body
Vision and Posture
• Visual input for postural control helps to fixate
the position of the head and upper trunk in
space
• Maintaining the center of mass of the trunk
balanced over the arches of the feet
• Studies involving patients with visual vertigo –
visual distortion markedly reduced postural
control
• Visual disorders correlated with postural
deformity as seen in scoliosis
Vision
• A role in the regulation of upright posture
• Maintaining the head in space
• Alterations in head posture may develop
secondarily to visual changes
• Studies show people wearing glasses may
demonstrate a change in head position
• People who wear multifocal lenses tend to
exaggerate forward head posture to use
the lenses
• Refraction problems (vision)
– sensorial exteroception of the eye
– convergence problems (proprioception)
– Refraction disorders
• myopia, astigmatism, hypermetropia which are
generally recognised and treated
• convergence disorders are very rarely diagnosed.
• Remove head tilt
• Child is instructed
to look up and
down for
approximately 1520 seconds
• If head tilt continue
move on…..
• Identify tropia
– Deviation of the eye
from the normal
position
HYPO
Note the weak eye
A convergence defect never corrects itself, it generates a new body
image which functions with the defect and the postural disorder that
accompanies it. If one has a convergence defect, in the absence of
treatment, it is for life!
• Asymmetrical oculomotor tension leads to
asymmetrical muscular tension cervical spine
• Lack of ROM of the neck
• Neurological link between the muscles of the eye
(III, IV, VI) and the cranial nerve XI
• They connect via the sensory division of the V:
upper trapezius and SCM are related and
dependent on the eye
• Neuro link between the first cervical nerve and
the XI, the sub occipitals are involved.
IN CHILDREN;
· Easily fatigued;
· Diminished intellectual abilities;
· Difficulties at school (lazy or turbulent
children);
· Dysgraphia;
· Spelling difficulties;
· Difficulties in learning to read;
· Poor performance in sports activities;
· Short legs in children.
• Examiner identifies
depression or
elevation of eye
movements
ABD
ADD
D E
D
E
• Note horizontal deviations:
• Intorsion – top of
the eye turns
inward
– Superior Oblique
• Extorsion – top of
the eye turns out
– Inferior Oblique
Visual Input
• Neuronal relay is based upon relative
perception
• Higher cortical functions are necessary to
differentiate between a fixed person within
a moving environment, or a moving person
within a fixed environment
• Postural corrections are made in the
direction of visual stimulation
• Afferent stimulation differentiates who is
moving or what is moving
• Even small changes in posture can occur
resulting from changes in light or
subconscious threshold
• Real-time posture does not receive much
contribution from higher-level processes
• Infants learn to assume a sitting position in
response to visual cues in their
environment
• Repetitive practice of sitting and heighten
sense to visual variables develops
visuomotor coordination
Oculomotor Proprioception
• Dual-control system is responsible for afferent
input into the oculomotor nuclei
• One pathway serves to generate eye rotations
• Second pathway provides sensory information
regarding eye alignment and stabilization
• Proprioception passes through the optic tract
nucleus, rostral portion of the superior colliculus
Superior Colliculus
• Essential role in head and eye orientation
and coordination
• Important in the integration centers for the
extraocular proprioceptive pathways and
the trigeminal nucleus
• Extensive reciprocal feedback pathway
with the reticular formation
• The trigeminal nerve provides
sensation to the face and
contains both sensory and
motor aspects.
• The sensory component
provides tactile, proprioception
and Nociception afference of
the face and mouth. The motor
component is for biting,
chewing, and swallowing.
• A complete sensory map of the
face and mouth converge and
communicate through CN V,
VII, IX and X. The counter
parts of the dorsal horn and
dorsal column nuclei contain a
complete sensory map of the
rest of the body.
Face Tapping
Fixing the Head and Trunk in
Space
• Stabilizes the visual field for gaze
stabilization
• Stabilizes the center of mass of the head
and trunk within feet support
• Minimizes the external stress acting upon
head and trunk
Vestibular Input
• Provides sensory input about sustained postural
stimulation
• Components utricle, saccule (linear
translations), 3 semicircular canals (rotations)
• Utricle (head tilts) and saccule (head position
relative to visual field) provide head position
relative to gravity
• Utricle and saccule transmit to brainstem and
cerebellum
Transmission
• Afferent information is transmitted along the
vestibular nerve
• Vestibular nuclei receives from the vestibular
nerve, the cerebellum and the optic tract
• Vestibular nuclei projects to the thalamus,
superior colliculus, reticular formation, cerebellar
flocculus, and lower vestibular nuclei
• Of special interest is the lateral vestibular
nucleus or Deiter’s nucleus projects to the
vestibulospinal tract
• Heel-to-toe test
– Age 6 years hold
posture for at least
7 seconds
– Observe arm
position
– Observe feet for
navigation
• Start with
dominant leg eyes
open and eyes
closed
– 6 year old should be
able to stand in EC
posture for 10
seconds
• Repeat to the
other side
• Examines the length
of time nystagmus
last following rotation
of the child
• Child in chair, head
flexed, 10 spins in 20
seconds
• Normal: lasts 7-14
seconds
• <7=hypo
• >14=hyper
• Neurological system cannot regulate the
amount of information bombarding the
CNS
• Sensory overload
• Brain unable to ignore all the vestibular
information
• After playing children may complain of an
upset stomach or dizziness
• Does not receive or correctly process
information about movement, changes in
direction, and relationship to gravity
• The child will have a difficult time
determining if they are up or down
• Low muscle tone
• Poor equilibrium
• Hyper
– Slow swinging
– Rocking
– Slow linear
movements
– Jumping
– Directional change
– Linear walking
– Linear movement
• Hypo
– Spinning
– Swinging
– Jumping
– Accelerating
decelerating
– Changing directions
quickly
Vision and Vestibular
• Constantly interact for upright posture and
tone
• Reflexive modulation
– Vestibulo-ocular reflex
• Tract modulation
– Vestibulospinal tract
– Dorsal and ventral spinocerebellar tract
Vestibulo-ocular Reflex (VOR)
• Compensates for head rotations or
accelerations
• 3 components
– VOR detects rotations through semicircular
canals
– VOR detects linear acceleration of the head
via the utricle and saccule
– Ocular counter-rolling response or optokinetic
reflex adapting eye position during head tilting
and rotation
The Key is Integration
• The integration of the head and eyes for
body posture is the VOR
• The cerebellar flocculus is responsible for
integrating and executing the efferent
corrections of the VOR
Cerebellum Development
• Characterization of the cerebellar territory at the
midbrain-hindbrain boundary
• Formation of two compartments for cell proliferation: first,
the Purkinje cells and the deep cerebellar nuclei arise
from the ventricular zone of the metencephalic alar plate;
second, granule cell precursors are formed from a
second compartment of proliferation, i. e. the upper
rhombic lip (6 to 8 weeks gestation)
• Inward migration of the granule cells: granule precursor
cells form the external granular layer, from which
(continuing into the first postnatal year) granule cells
migrate inwards to their definite position in the internal
granular layer
• Formation of cerebellar circuitry and further
differentiation
Purkinje Cells
•
Largest neurons in the human brain
•
Large number of dendritic spines
•
Parallel fibers make relatively weaker
excitatory synapses to spines in the
Purkinje cell dendrite, whereas
climbing fibers originating from the Inf
Olivary Nuc in the Medulla provide
very powerful excitatory input to the
proximal dendrites and cell
•
Send inhibitory projections to the deep
cerebellar nuclei, and constitute the
sole output of all motor coordination in
the cerebellar cortex.
Medial and Lateral Vestibulospinal
Tracts
• Efferent equivalents of the VOR
• Modulating motor to the axial and
appendicular muscles for rapid postural
adaptations
• The cerebellum where afferent input from
visual through the vestibular nerve and
cervical mechanoreceptors is collected
• Compensation is made by the trunk and
extremities to the head position
Vestibulospinal Tract
• Reflexive correction to sudden
perturbations in static upright posture
• Visual is responding to constant postural
adatations
• The vestibular apparatus through the
vestibulospinal tract is quicker to respond
to slight postural disruptions, allowing for a
faster response from the skeletal postural
muscles
Dorsal and Ventral Spinocerebellar
Tracts
• Sensory signals to the cerebellum
• Through joint, skin, muscle spindles and
GTO afferents
• Mapping position sense of the lower
extremity
• Coordination for locomotion
• Spinal interneurons between thoracic 1
and lumbar 2
Trouble in Development
Cervical Mechanoreceptors
• Head on neck
position
–
–
–
–
Facet joints
Capsule
Spinal ligaments
Proprioceptive input
from cervical muscles
Chiropractic
Cervical facets
contribute to
postural
orientation, injury
may produce
postural
symptoms like
vertigo and
dizziness
• Facets MR provide afferent postural input to
trochlear, abducens, spinal trigeminal, central
and lateral cervical and vestibular nuclei,
cerebellar flocculus and vermis
Posterior Longitudinal Ligament
• Extensive sensory
input for postural
control
• Provided by Pacinian
and Ruffini corpuscles
• Afferent connections
with the gracilis and
cunneatus, vestibular
nuclei, thalamus,
sympathetics, and
muscle spindles
Cervical Muscles
• The upper cervical
spine contains a
higher density of
muscle spindles than
in any other spinal
region
• Affected by visual
field and vestibular
apparatus
Cervical Torticollis
• Responding to 15 min of
cervical vibration
• Muscle spasm may be
associated with aberrant
afferent input relaying
head position to the CNS
• Cervical input plays a
major role during
locomotion and less in
coordinated static posture
Visual and the Cervical Spine
• Cervico-ocular reflex
• Cervicocollic Reflex
• Vestibulocollic
Cervico-ocular Reflex
• Orient eye
movements to
changes in neck and
trunk positions
• The trunk, cognitive
interpretation, retinal
information contribute
to the plasticity of the
COR
• Intact optokinetic
reflex
Cervicocollic Reflex
• Orient the position of the head in relation
to disturbed trunk posture
• Like a stretch reflex
• Reflexive correction of cervical spine
position through co-contraction of specific
cervical muscles by activating muscle
spindles
• Communication between CC and VCR
Vestibulocollic
• Evaluate through perturbations of the head in
the horizontal plane.
• Dissociated from the vestibulospinal reflex which
orients the extremities to the position of the head
and neck
• Reflex based on stimulation of cervical afferents
directly
• Globally through the reticular formation for
interpretation throughout the CNS and sensitivity
Development of Postural Control
• Infant’s orientation at
2 months is
dependent on visual
cues for head and
trunk
4 to 6 Months
• Postural reflexive
mechanisms such as
crawling begin to
incorporate joint MR
and the vestibular
system
Head Control
Head position relative to gravity
trunk and lower extremity control can be learned
using a fixed reference point
Pelvo-ocular reflex
• Neuromotor responses are coordinated in
the lower extremities before trunk and
upper extremities
• Serves to orient the body region in
response to head position and anticipatory
visual reference cues
8 – 14 Months
• Infants can process
multiple postural
sensory stimulation
Biomechanical Development
• Structural and functional development of
the spine appears to result from upright
posture in gravity
• Sagittal curves allow for balance between
strength and flexibility
• Microgravity to gravity
• Forces experienced a
birth develop the
muscle bone lever
system
• Balance of tone
Progression of Curves
Network of Postural Control
•
•
•
•
Head upright
Stand upright
Stabilizing trunk, pelvic, lower extremities
Global posture and spine balancing head,
neck, trunk over the base of support = feet
Ossification
• Active muscular stabilization increases the
stress on musculotendinous junctions and
osseous attachments for bone
development
• Standing repeatively coordinates
neuromotor control of the lower extremities
and spine integrating head and neck with
the cerebellum
Center of Mass
•
•
•
•
Tone
Body Image
Balance
Performance
Abdominal Tone
Center of Mass
Glute Max
Abdominals
Hamstring
Quadratus Lumborum
Piriformis
TFL
Upper Traps
SCM
Problems w/ Core
•
•
•
•
Visceroptosis
Back pain
Poor diet/lifestyle
Exercising on machines
Spine Vol 30(21), 1 November 2005,
pp2388-2392
• Spinal Kyphosis Causes
Demyelination and Neuronal Loss in
the Spinal Cord
• Conclusions: Progressive kyphosis of the
cervical spine resulted in demyelination of nerve
fibers in the funiculi and neuronal loss in the
anterior horn due to chronic compression of the
spinal cord. These histologic changes seem to
be associated with both continous mechanical
compression and vascular changes in the spinal
cord.
Single-Leg Stance BalanceTest
• Maintain balance EC
for 30 seconds
• Repeat four times to
reach peak
performance
•
•
•
•
20-49yrs/24-28 sec.
50-59 yrs/21 sec.
60-69 yrs/10 sec.
70-79 yrs/4 sec.
Short Foot Lever
• Balance training
begins with careful
attention to formation
of a good arch in your
foot without bending
your toes (BullockSaxton, et al., 1993,
Janda, Va'vrova'
1990;Janda, Va'vrova'
1996)
Sensory Motor Training
Stabilization From the Ground Up!