Abnormal Postural Control Flashcards
what factors contribute to abnormal postural control
- behavior (fear, anxiety)
- sensory loss
- age-related changes
- paresis/plegia
- pathologic synergy
- abnormal motor tone
- cognitive impairment
- impaired coordination
- loss of feedforward/feedback
the ability to maintain center of gravity within base of support
balance
falls are common across all _______ pathologies due to impairment of sensory, motor and cognitive deficits that impact reactive and proactive postural control
neurologic
what percent of falls require medical attention
15
what does impaired steady state balance lead to
- unable to stand or sit static without loss of balance
- limits overall function and ADLs
- abnormal postural alignment may be a function of disease process
- abnormal postural alignment may cause abnormal postural reactions
describe the typical stooped posture of a pt with PD
- forward head
- rounded shoulders
- excessive T/s kyphosis
- flattened l/s lordosis
- ppt
inability to move properly; lesions of the motor cortex or descending motor pathways (UMN) produce significant signs and sx that impact normal motor function and postural control
motor dyscontrol
signs and sx of UMN
- abnormal reflexes (palmar/plantar grasps, babinski)
- hypertonia/spasticity/clonus
- paresis/plegia
- abnormal timing/coordination of movement
the ability to generate sufficient muscle tension for the purpose of posture and movement (based on number of motor units recruited, type of units recruited, frequency of action potentials)
strength
inability to generate normal levels of force –> what are the two types
weakness
- paresis
- plegia
what is the difference between paresis and plegia
paresis: mild weakness
plegia: severe to complete loss of strength/paraylsis (hemiplegia, paraplegia, quadriplegia, tetraplegia)
coupling together of muscle groups to produce more efficient movement
synergy
mass patterns of movement in stereotypical presentation; limits fractionation; movement outside of a fixed pattern is not possible
abnormal/pathological synergy
inability to move single joints without activating movements in other joints
limited fractionation
used to rehabiliate pts post stroke; focuses on synergistic muscle patterns progressing through various stages on involuntary and voluntary movement
Brunnstrom method
stage I of Brunnstrom’s Stage of Recovery
flaccidity
no voluntary or reflex activity present
stage II of Brunnstrom’s Stage of Recovery
spasticity begins to develop
synergy pattern begins to develop, may appear as associated reactions
stage III of Brunnstrom’s Stage of Recovery
spasticity reaches peak
movement synergies can be performed voluntarily
stage IV of of Brunnstrom’s Stage of Recovery
spasticity begins to decrease
deviation from movement synergy is possible, limited combo of movement
stage V of Brunnstrom’s Stage of Recovery
spasticity essentially absent
isolated and combo movement evident, coordination may be impaired
stage VII of Brunnstrom’s Stage of Recovery
return to normal function
return of fine motor skills
describe UE and LE flexor synergy patterns
- UE: scapular retraction and elevation, shoulder ER and abd to 90, elbow flexion, FA supinated, wrist and finger flexion
- LE: hip flexion and abd and ER, knee flexion to 90, ankle Df and inversion, toe extension
describe UE and LE extensor synergy
UE: scapular protraction, shoulder IR and add, full elbow extension, FA pronation, wrist and finger flexion
LE: hip extension and add and IR, knee extension, ankle PF and inversion, toe flexion
what is the name for full body extensor tone
decerebrate
amount of stiffness in a muscle noted during PROM
muscle tone
hypotonicity is associated with deficits in
cerebellum, T21, developmental delay or LMN lesion
hypertonicity is associated with deficits in
motor cortex or descending motor pathways (UMN)
two types of hypertonicity
rigidity and spasticity
what is rigidity
coactivation of antagonists that result in resistance in PROM t/o the range that is not velocity dependent (ex: PD)
what is spasticity and what is it characterized by
- velocity dependent resistance to PROM; overactive stretch reflex
- tendon jerks, excessive coactivation of muscles, associated movements, abnormal synergies, abnormal posturing of the limbs or trunk
spasticity is involuntary and occurs due to injury to what structures and is often associated with what injuries
- cortex, basal ganglia, thalamus, brainstem, central white matter, spinal cord
- TBI, stroke, MS, SCI, CP
spasticity is the loss of higher level inhibitory influence due to pathology that leads to lower level movement strategies and reflexes to appear such as
- abnormal synergy patterns
- primitive reflexes
what is used to grade spasticity
MAS
looking at center of pressure excursion (how much the body moves in quiet standing); typically assessed using force platforms (A-P and M-L speed and excursion); increased with pathology
postural sway
what pathologies can impact postural sway
CP, CVA, TBI
types of sway associated with locations of cerebellar lesions
- upper vermal/intermediate ant lobe: increased A-P sway
- lower vermis: increased omnidirectional sway
- lesion of spinocerebellar afferents (Friedreich’s disease): large amplitude lateral sway
what conditions lead to increased sway area, velocity and asymmetry
PD, down syndrome
balance reactions in postural sway deficits lead to LOB due to ______ and toward ____ side
- delay in response
- toward the affected side
what are 4 things associated with impaired response to perturbation
- delayed motor recruitment in response to perturbation
- co-activation (results in stiffness - unable to recover following perturbation)
- delayed activation of postural responses (slower sequencing, timing and amplitude of postural muscles in paretic limb)
- impaired stepping strategy (delayed activation of postural muscles or lateral or cross stepping)
what part of the body needs to be controlled before anything else
head
- HAT: head –> arms –> trunk
what is a good prognostic indicator for functional outcomes with TBI/CVA and what are good measures to be used with stroke
sitting balance
- postural assessment scale for stroke patients (PASS)
- function in sitting test (FIST)
recovery of function in sitting follows ______ sequence
top-down
coordination deficits develop due to what with impaired postural control
- sequencing
- timely activation
- adaptation
neurological deficits can impair sitting/standing postural reactions
impaired postural reactions
describe sequencing problems associated with coordination issues with impaired postural control
inability to sequence proper muscle firing due to weakness or increased tone
describe timely activation coordination issues with impaired postural control
activation time may be longer and amplitude smaller on affected side
described impaired adaptation with coordination issues with impaired postural control
inability to adapt sequencing and amplitude based on demand; altered feedback and feedforward control mechanisms due to deficits
what is anticipatory postural control reliant on and what structures does it involve
- reliant on experience and ability to learn
- involves supplementary motor cortex, basal ganglia, and cerebellum
an example would be not being able to tell how much force/energy is needed to pick up an object (using too much or too little force)
impaired anticipatory postural control
what conditions with impaired anticipatory postural control will be altered with changes in movement (abnormal tone, weakness, coordination deficits)
TBI, CVA, MS, PD, CP
what conditions that have perception or sensory system affected will alter anticipatory postural control
dementia, TBI, PN, MS, vestibular, lack of vision/hearing
coordination and timing problems are associated with lesion to
cerebellum and basal ganglia
uneven movement trajectory, not smooth, loss of coordinated synergy, difficulty with movement error correction would suggest lesion where
cerebellum
sx/outcomes of cerebellar lesion
- ataxia
- dysdiadochokinesia (inability to do rapid alternating movements)
- dysmetria (inability to judge forces)
- delated reaction time
- inability to stop/start/change directions
- inadequate force generation, intention tremor
tremor that only occurs with movement and a lesion where would lead to this
- intention tremor
- cerebellum
hypokinetic disorders due to lesion to basal ganglia
PD (bradykinesia, rigidity, resting temor)
hyperkinetic disorders associated with lesion to basal ganglia
chorea, athetosis, dystonia
lack of coordination of movement; typically described as undershooting or overshooting of arm, leg or eyes; unable to judge distance or scale
dysmetria
involuntary, jerky movements; appear random, continuous and unpredictable
chorea
involuntary writhing movement; typically slow; does not have sustained postures
athetosis
repetitive twisting or writhing movement that are repeated and frequently held
dystonia
inability to maintain postural control while performing multiple tasks (increased sway, LOB reactions, poor quality of movement, decreased accuracy, change in BOS, diminished cognitive performance, loss of attention to task)
dual task interference
what is posture second strategy
prioritization of cognitive task over posture
what conditions is dual task interference tested in
PD, TBI, post stroke, dementia, Alzheimers, CP, developmental coordination disorder
postural control and aging
- sensory and motor processes decline (depends on genetics, lifestyle, environment)
- we are what we eat and do (cannot change genetics)
- aging is not homogenous
is aging homo or heterogenous
heterogenous
____ max force production loss by 65, ___ muscle mass loss each decade after 30
- 40%
- 3-5%
what MSK factors are influenced by aging
muscle strength, muscle mass, elasticity of contractile tissue, bone density, BALANCE
loss of hearing
presbycusis
declining visual acuity
presbyopia
minimum amount of light needed to see - how does it change in aging
- visual threshold
- increases due to decline in retinal function
lose of central vision
macular degeneration
clouding of lens of eye
cataracts
____ changes result in increased postural sway in quiet standing and difficulty when environmental lighting changes
visual
visual changes with age
- increased visual threshold
- visual field changes
- visual acuity changes (macular degeneration, cataracts, loss of peripheral vision
- loss of depth perception
cardiac changes with age
- decreased cardiac output
- decreased max HR
- decreased stroke volume
- increased resting BP
- increased exercise BP
amount of blood pumped from heart per minute
cardiac output
amount of blood pumped from L ventricle per beat
stroke volume
older adults with and without balance problems show changes in the motor system that limit their ability to adapt to changes in the environment leading to
increased fall risk
older adults often have ______ when holding something else in their hand; give example
- delayed reaching response
- no attempt to reach for a handrail if holding an assistive device
vibratory threshold at the great toe _____ 3-fold by age 90 –> suggests loss of protective sensation in the foot and ankle
increases
tactile sensation decreases as a result of diminished quality and quality of what
meissner end organs and pacinian corpuscles
at what age is 40% loss of vestibular hair cells
70
___ loss of vestibular nuclei cells per decade between 40-90 y/o
3%
vestibular changes in older age limits the ability of the vestibular system to act as a corrective system when there is conflicting information from visual and somatosensory system leading to
dizziness and unsteadiness in busy environments
greater _____ of positional vertigo and dizziness with aging
increase
by age 80, _____ likelihood of having vestibular dysfunction
85%
pulmonary changes in older adults
- increased residual volume
- increased respiratory frequency
- decreased vital capacity
volume of air still in lungs after max expiration
residual volume
max amount of air that can be exhaled
vital capacity
endocrinologic changes in older adults
- decreased metabolic rate
- decreased lean body mass
- increased body fat
are balance problems just a result of aging
NO
what sensory systems do older adults use as input for balance
vision and somatosensory
changes in posture with aging
- forward head
- increased TS kyphosis
- flattened lordosis
- decreased knee and hip flexibility
- loss of strength
- decreased ankle flexibility and strength
- changes in gait patterns causing less toe off and floor clearance
gait changes with aging
- cautious
- cadence, velocity, stride length reduce
- stride width increases
- double support time increases
- delayed initiation
- increased difficulty stepping over objects
- dual tasks problems
