Applied Neuro Exam II

What are the three theories for motor control?

-reflex-hierachial model
-motor program theory of motor control
-dynamic systems theory of motor control

Which theory demonstrates that a stimulus will elicit a response? Give an example of this model

reflex, ATNR

What motor theory is a "top-down" approach where higher cortical levels control lower levels

What is its biggest limitation?

hierarchal theory, only explains pieces of motor control

What does the motor program theory say? This theory was developed alongside ______

There are stored neural circuits for movement patterns/synergies, Schmidt's theory of motor learning

Motor program theory is an open or closed loop system? Why?

open - allows for movement without sensation or time for sensation to provide feedback

Set of general rules of the spatial-temporal patterns for a type of movement

motor program

The dynamic systems theory of motor control states that movement emerges from what three things?

individual, task, environment

Dynamic systems theory states that movement comes together from _____

an interaction of systems

Give an example of dynamic systems theory with postural control

vision first to map and then start to use somatosensory

What tends to be the most critical input for proactive balance?

vision

Dynamic systems theory states that our degrees of freedom is controlled through _______

top down synergies

What happens in the black box of neural control?

stimulus identification, response selection, and response programming

What are the stages of motor output?

initiation, execution, termination

What are the motor planning areas in the pathway of normal movement?

premotor, SMA, and sensorimotor cortex

What are the control circuits in the pathway of normal movement?

cerebellum and basal ganglia

What is the sensory feedback triad? What type of feedback do they all contribute to?

vision, vestibular, and somatosensation - intrinsic feedback

What parts of the CNS control vision? Vestibular? Somatosensory?

vision - cortex
vestibular - brainstem + cerebellum
somatosensation - SC

What are the three fundamental types of movement?

ambulation, posture, reach/grasp

CNS regions that drive ambulation? Posture? Reach and grasp?

ambulation - brainstem plus spinal regions
posture - brainstem
reach and grasp - cerebral cortex

Postural control ascending tracts go through what structures to adjust to sensory input?

basal ganglia and cerebellum

Ideal alignment is what stance? Why?

quiet stance, reduces energy expenditure

Different between quiet and static posture?

quiet posture has decreased muscle tone
static posture has active muscle tone and some movement sway

What is an example of dynamic steady state balance?

gait

What is an example of steady state balance?

standing

Input for steady state/reactive balance is mediated by what components?

vision, vestibular, somatosensory

Which brain structure adjusts force/amplitude of movement during reactive balance and has control over the postural set?

basal ganglia

What is the input for anticipatory/proactive balance mediated by?

vision

Which structure of the brain works on output control for anticipatory/proactive balance?

cerebellum (predictive)

Postural muscles can engage ____ ms prior to the muscles that execute the voluntary movement

90-100 ms

The cerebellum controls ____ of postural responses whereas the basal ganglia has control over the ___

adaptation, postural set

Task oriented approach is also known as ____

motor control framework

What are the three assumptions of normal movement based on task oriented approach?

-emerges from an interaction of multiple systems
-movement is organized around a behavioral goal
-sensation is essential to predictive and adaptive control of movement

What are the two assumptions of movement problems based on task oriented approach?

-results in impairment within one or more of the systems involved in movement

-what is observed is NOT just a result of the lesion but also the efforts of the remaining systems to compensate to maintain function

What are the six core tasks for movement observation/task analysis?

-sitting
-standing
-sit to stand; stand to sit
-walking
-step up/down
-reach, grasp, and manipulation

_____ is the cornerstone of PT examination of functional abilities

Task

What does HOAC stand for?

Hypothesis-oriented algorithm for clinicians

What are the steps in task oriented approach to movement analysis

1. observe and describe movement

2. develop hypotheses of underlying causes of movement problems

3. prioritize hypotheses to test

4. hypotheses testing (select appropriate test and measures

What are the three intervention approaches for neurologic PT?

remediation = restoration/recovery (changes in systems/person)
compensation = alternation of environment/task
prevention = management of anticipated problems

What are the two components of postural control

orientation/stability

Ability to maintain the relationship between body segments and between body and environment for a task (alignment)

postural orientation

Describe postural stability

being able to balance COM in BOS (balance)

What are the task constraints for postural control?

1. balance control (steady state, proactive, reactive)
2. feedback control
3. feed-forward control

What is feedforward control? Expected or unexpected postural disturbances?

control that allows people to anticipate problems before they arise
*expected postural disturbances*

What is feedback control? Expected or unexpected postural disturbances?

mechanism for gathering information about performance deficiencies after they occur
*unexpected postural disturbances*

What are the environmental constraints for postural control?

support surfaces, sensory context (difference in visual/surface conditions), and cognitive load

What is steady state balance?

muscle tone that keeps the body from collapsing in response to the pull of gravity

What is postural muscle tone?

activation of anti-gravity muscles to prevent body from collapsing when we stand/sit upright

T/F: Performance of a secondary task is always detrimental on postural control

False - PTs need to assess balance under dual task conditions

What are the limits of stability?

Area within which a person can move their COM without changing the BOS

What are the four motor strategies observed in reactive balance control?

ankle, hip, step, reach to grasp

What is fixed support reactive balance control? What strategies are used?

BOS does not change to maintain stability (hip/ankle strategies)

What is change-in-support reactive balance control

BOS changes to maintain stability (reach to grasp + step)

Reactive balance control can occur in what two directions? What is the reactive balance control recruitment order for both of these directions?

anteroposterior and mediolateral
ankle strategy - hip strategy - change-in-support strategy

How are muscle synergies refined/tuned?

They are refined and tuned in response to changing demands in the task/environment (adaptability)

The CNS uses anticipatory/proactive processing to ____

control actions

What is anticipatory balance control necessary for?

lower extremity functioning

This system provides the CNS with position and motion information about the body with reference to supporting surfaces and overall integration

somatosensory system

Provides CNS information about position and movement of the head with respect to gravity and inertial forces

vestibular system

What is the concept of dual-task interference with our cognition as it relates to postural control?

Attentional demands vary as function of sensory cortex - important for PTs to assess balance under both single and dual task conditions

What are the two spinal contributions to postural control?

-orientation via tonic activation of extensor muscles for weight support
-directionally specific responses to perturbations

What are the brainstem contributions to posture control?

regulation of posture tone and automatic postural synergies

Falls are the ___ leading cause of death in the elderly

5th

What is a key change that occurs with somatosensory as we age?

increased latency especially in pts with neuropathy

Alignment assessment for steady-state balance looks at what?

-relationship of body segments to one another
-position of body with reference to gravity and BOS

This assessment assesses steady state balance during quiet stance

postural sway assessment

COM shifts where with aging?

posteriorly

Does spontaneous sway increase or decrease in healthy older adults with dual tasks?

increases

Latency is greater in the single or dual task conditions for older adults?

more in dual

Population characteristic that has the greatest muscle latency?

older adults with balance impairments

Muscular activation increases or decreases with dual task in young populations?

increases

Muscular activation with dual-task increases or decreases in older populations with balance impairments? Why?

decreases because cannot turn muscles on fast enough or at right magnitude to be effective

What is a major problem in quiet stance? What can this lead to?

postural alignment abnormality can change the limits of stability

What types of abnormalities can change the limits of stability?

asymmetry in WB
restricted ROM at joints
muscle and postural tone

Major problem in perturbed stance?

impaired coordination of muscle synergies

Conditions affecting what structures can lead to impaired anticipatory/feed-forward control?

basal ganglia (Parkinson's)
cerebellar issues
visual issues

What strategies are used to control dynamic posture?

step strategy
reach strategy

How do we examine functional limits of stability?

Center of pressure excursion during voluntary leaning

What are measures of reliability vs measures of validity?

reliability: interclass coefficient/standard error of mean
validity: sensitivity, specificity, likelihood ratios

What are the three measures for responsiveness

MDC, MCID, Ceiling and floor effects

Minimal Detectable Change (MDC)

the amount of change that just exceeds the standard error of measurement of an instrument

-how much error with the tool

Minimum Clinically Important Difference (MCID)

Is the smallest difference in a variable that signifies an important rather than trivial difference in patient condition.

-measures tied to an outcome

Sensory organization test looks at what?

changing conditions to test sensory triad

Condition 1 of SOT? Accurate and inaccurate inputs?

normal vision with fixed surface
accurate - triad
no inaccurate

Condition 2 of SOT? Accurate and inaccurate inputs?

eyes closed with fixed surface
accurate somatosensory and vestibular
no inaccurate

Condition 3 of SOT? Accurate and inaccurate inputs?

sway referenced vision with fixed surface
accurate: vestibular and somatosensory
inaccurate: vision

Condition 4 of SOT? Accurate and inaccurate inputs?

normal vision with sway surface
accurate: vestibular, vision
inaccurate: somatosensory

Condition 5 of SOT? Accurate and inaccurate information?

eyes closed with sway surface
Accurate: vestibular
inaccurate: somatosensory

Condition 6 of SOT? Accurate and inaccurate information?

sway vision with sway surface
accurate: vestibular
inaccurate: vision, somatosensory

what conditions included in the mCTISB?

1,2,4,5

Vestibular challenged most in which conditions?

5 and 6

Children 1-7 will show abnormal responses in what conditions? Why?

conditions 3-6

Somatosensory accurate in which conditions of CSTIB? which inaccurate?

accurate in 1-3
inaccurate in 4-6

Vision absent in which conditions? Accurate in which conditions? Inaccurate in which conditions?

2 and 5
accurate in 1 and 4
inaccurate in 3 and 6

biggest difference between younger and older adults in MTCISB?

vestibular system

Stepping pattern generator is an example of what kind of motor theory?

motor program theory

What motor neuron pool is the primary driver of fractionated movement?

lateral motor neuron pool

What motor neuron pool is primary driver of walking?

medial motor neuron pool

Describe the activation of flexors/extensors in the step pattern generators of the lumbosacral spine?

ipsilateral flexors are activated during swing and contralateral extensors during stance

What are the three motor control requirements/goals of ambulation? Whats the only difference with sit to stand?

1) progression
2) postural control
3) adaptation

sit to stand is stability instead of postural control

What is the goal of the cerebral cortex in ambulation?

provides a goal/controls overall movement plan