constraints on motor control Flashcards
Apraxia
inability to carry out an intended movement even thought sensation, movement ability, and coordination are all capable of functioning properly
apraxia is considered
primary perceptual impairment
apraxia is associated with damage to what side of the brain
left
pt. with spatial relation disorders will have difficulty with
perceiving relationships b/w
- self w/ other objects
- other objects and self
multiple objects
(position in space)
Body image and body scheme disorders are described as
decreased awareness of body parts, their relationship to each other, and the environment
an example of body image/ body scheme disorders is
unilateral neglect
unilateral neglect
an inability to perceive and respond to stimuli on one side of the body
perception
is making sensory information meaningful
what is an example of perception with the body
verticality
what is the difference b/w visual vertical and postural vertical
postural vertical is somatosensory information determined without visual input
patient with vestibular deficits may have difficulty with
- gaze stabilization
- posture
- balance
where can vestibular damage occur
in the cortex or the periphery
patients with visual deficits may have difficulty with
- depth perception
- visual fields
- acuity
- oculomotor control
list the locations of somatosensory lesion
- dorsal column/medial lemniscus
- anterolateral lesion
- somatosensory cortex lesion
dorsal column/medial lemniscus lesion
loss of
- discriminative touch
- light touch
- kinesthesia
anterolateral lesion
loss of
- pain
- temperature
- coarse touch
- kinesthesia
somatosensory cortex lesion
loss of
- proprioception
- two point discrimination
- sterognosis
- touch localization
sterognosis
is being able to identify an object based on the perception of its structure
list primary neuromuscular impairments
- paresis
- spasticity
paresis
weakness from loss of cortical drive
what is a constraint
anything that constrict, restrain, restrict, limit the individual
constraints w/n the individual are known as
impairments
Primary Cognitive System Impairments
- arousal/level of consciousness
- attention
- orientation
- memory
how does level of consciousness/arousal correlate to movement
- must be alert enough to respond to environmental stimuli
how does attention correlate to movement
- inability to focus on task affects motor learning
selective attention
ones ability to attend to something w/o becoming distracted
orientation impairments can be described as
lack of situational awareness
what do most people lose orientation to ?
place and time
memory impairments
decreased ability to process, store, and retrieve info
what should you do when treating patients with a decreased response time
slow down, lots of pauses, and give them time to process what you are saying
Primary Neuromuscular impairments affecting the motor system
- mm weakness
- coordination problems
- involuntary movements
- abnormalities of mm tone
- abnormal synergies
synergy
pattern of movement
mm weakness
inability to generate adequate level of force
paralysis/plegia
total/severe loss of mm activity
primary mm weakness is a result of
lesions in descending motor paths –> inability to recruit and or modulate motor neurons
Neural aspects of force production
- # of motor units recruited
- type of motor unis recruited
- frequency of discharge
musculoskeletal aspects of force production
prolonged paresis or disuse can cause secondary changes to muscle tissue such as atrophy
describe the difference b/w weakness in UMN lesion and weakness in ortho patients
in a neuro pt. the capacity to generate force in an isolated mm does not predict the mm ability to work with other mm like it does for ortho pt.
describe an example of positioning affecting mm
STNR (head and arms go together, lower body does the opposite
in neuro pt. weakness may be
in the delivery or lack of delivery to the mm not in the mm directly
why is MMT not the best test for neuro pt.
b/c MMT test mm ability to function in isolation
- neuro pt. are unable to isolate the mm
how does change in body positon influence change in reflex, tone, and synergies in an abnormal pt.
a pt. may have anti-gravity movement in one position but not in the other.
tone vs. synergy
- tone is observed in a resting state
- synergy is observed during movement
coordination impairment is a classic disorder involving what brain structures
- Basal ganglia
- cerebellum
coordination
sequencing, timing, grading of activation of multiple mm groups
incoordination
movements that are awkward, uneven, or inaccurate
incoordination is associated with lesions in the
- motor cortex
- basal ganglia
- cerebellum
- proprioceptive system
incoordination is influenced by
peripheral factors (change in mm, tendons, fatigue)
automatic postural reactions of the LE for normal sequencing
ankle –> knees–> hip –> trunk
co activation causes the body to become
rigid
sequencing problems include
- activation of mm/ groups in wrong sequence
- activation of mm/groups inappropriate for the action
- co-activation
- impaired inter-joint coordination
impaired inter- joint coordination
movement decomposition or movement at one joint at a time
inter joint coordination impairments is associated with damage to what part of the brain
cerebellum
timing problems
problems initiating movement
- increase reaction time
- delayed movement time
timing problems can occur in what kinds of pt.
- CVA
- TBI
- PD
timing problems may be a result of
- inadequate force generation (weakness)
- decreased rate of force generation (power)
- cognitive factors
- altered sensory input/perception
decreased
- ROM
- motivation
- postural control
slowed movement time may be seen in pt. with
- CVA
- PD
- CP
- cerebellar damage
problems terminating a movement is seen in pt. with
cerebellar lesions
problems terminating movement may be due to
- inability to stop mm contraction/ control force production
- cognition
- sensory deficit
- poor posture
- pt. with preservation problems
dysmetria
inability to scale force, problem judging distance or range
dysmetria is a classic _____ impairment
cerebellar
hypometria is seen with
BG lesions- PD
hypermetria is seen with
cerebellar lesions
dysarthria
motor disorder of speech production
intention tremor is seen with
CB damage
resting tremor is seen with
PD pt.
check reflex
they can not terminate the motion
rebound phenomenon see in
cerebellar pt.
dysdiadochokinesia
difficulty with RAM - rapidly alternating movement
dystonia
involuntary, sustained mm contractions; twisting and repetitive movements, and abnormal postures
dystonia is associated with
BG disease progression
- high dosage of antiparkinsonian medication
associated movement
unintentional movement of one limb during voluntary movement of another
tremor
rhythmical, involuntary oscillatory movement of a body part
choreiform movement
involuntary, abrupt, rapid, irregular, jerky movement
choreiform movement is associated with
huntingtons - BG lesions
athetoid movement
slow, involuntary writhing and twisting
is spasticity and tone the same thing?
it is not the same thing but they co occur in pt. with UMN, cortical lesions of the corticospinal tract
spasticity in short
hyper-reflexia
spasticity
is velocity dependent stretch reflexes
spasticity is a result of
hyper excitability of tonic stretch reflexes
disinhibiton of spinal reflex
loss of cortical drive or direct damage to
- dorsal reticulo
- rebro
- vestibule
…spinal tracts
damage to the cortico-reticular fibers after supra-tentorial lesion produces
spasticity
what do mm spindles tell us
how much stretch the mm is experiencing
damage to corticospinal tract causes
flexor withdrawal reflex
what is the compensation for decreased cortical drive
increase in stretch reflex gain so a small drive signal produces a larger mm response
when is spasticity seen
it is not seen immediately after cortical lesion, develops over several weeks after neural damage
spasticity is seen to be
a sign of neuro plasticity of the brain adapting to a loss of descending control
what are the effects of spasticity on motor control
- loss of reciprocal inhibition
- increased sensitivity of motor neurons
- increased post action potential depression
How are stretch reflexes tested (spasticity)
- passive
- examiner provides a quick stretch stimulus
how does spasticity affect volitional movement
if a pt. moves too quickly, they can unintentionally trigger the antagonist inducing spasticity
what is an example of spasticity affecting volitional movement
rapid weight loading on a spastic ankle can cause clonus
how can patients with spasticity affecting their volitional movement counteract this
move slower
what is the problem with anti-spasticity medication
they are not selective
- inters w/ agonist and antagonist ability to contract
- reduce motor learning
what patients can benefit from anti-spasticity medication
- pt. whose function is severely restricted
- pt. whom increasing strength/motor learning is not a primary goal
abnormal tone (hypertonia)
tonic ongoing contraction of mm or mm groups at REST
- motor over-activity
what is the difference b/w hypertonia and spasticity
hypertonia has nothing do with velocity (doesn’t require any mm stretch)
what causes hypertonia
damage to corticospinal tract and damage/decreased cortical drive to BG
hypertonia is sensitive to
mm stretch and length
how can you temporarily decrease hypertonia
sustained stretch, prolonged lengthening
how does prolonged stretch decrease tone
sustained stretch is inhibitory action
flaccidity
too little tone at rest
how does tone fluctuate
- position of limb and body
- effort, pain
- temperature
- stress
how is tone tested
- limb is passive
- examiner provides a slow stimulus
what are we looking for when we test for tone
resistance to slow, even passive movement
how does tone affect volitional movement
- easier for pt. to move mm concentrically, difficulty w/ eccentric movement or relaxation
- difficult to move in opposite direction of hypertonic mm
why is it difficult to move in the opposite direction of hypertonic movement
- failure of reciprocal inhibition
- tonic drive to antagonist may exceed drive to agonist
for a pt. with high tone which mm contraction is easier
concentric mm contraction
what happens if you can reduce the effort need in a pt. with high tone
pt can perform the motion little better but may still compensate
abnormal synergies
characterized by mass movement and inability to isolate or fractionate joint motion from one another
abnormal synergies are common in
patients with UMN lesion
what causes abnormal synergies
abnormal co-activation of all mm in a normal synergistic group
how are abnormal synergies tested
- limb is ACTIVE
examiner request pt. do volitionally move the limb – in a synergy - out of synergy
associated reactions
involuntary motion in one part of the body with volitional movement of another part of the body
associated reaction is AKA
overflow phenomenon
can associated reactions occur bilaterally?
yes
- if hemiplegic, movement is abnormally synergistic
how do we test for associated reactions
observation
- request effortful, resisted movement on the non-hemiplegic side
- works with if pt. attention is elsewhere
rigidity occurs at what level
the level of basal ganglia
normal tone
readiness to move
describe the order of the tone figure
flaccidity > hypotonia> normal> hypertonia
hypertonicity on the tone scale
increased resistance to passive movement
hypertonicity is seen
later during recovery in Stroke, TBI pt.
hypotonia on the tone scale
decreased resistance to passive movment
hypotonia is seen in what kinds of pt.
- down syndrome
- spinocerebellar lesions
hypotonia is seen
earlier during recovery in stroke, TBI pt.
flaccidity on the tone scale
complete loss of tone, no resistance to movement
flaccidity is seen in what kind of pt.
- neural shock
- peripheral n. injury
flaccidity is seen
in the acute phase of pt. with stroke, TBI
what is a DTR
quick stretch of mm spindle
describe the order of the hyper-reflexia figure
absent > hypo-reflexia > normal > hyper reflexia (true spasticity)
describe the order of the abnormal synergies figure (brunnstromm)
no voluntary motion > volitional movement weak w/ incomplete synergies > synergistic movement only, full synergies possible > some out of synergy motion possible > independence from synergies> normal
task demands
- stability
- transitions
- mobility
- manipulation
- concurrent tasks (divided attention)
environment demands
- surface
- visual
- closed/open
- predictable/variable
- stationary/in motion
- distractions
the difficulty of an activity depends on what
- individual abilities and constraints
- demands of task
- the support or challenge provided by the environment
