Postural Control In Neuromuscular Disorders

Question 1

What is the relationship between CoM and BoS?

Answer 1

fundamental to maintaining balance and stability in both static and dynamic situations

For a person to maintain balance, the CoM must remain within the BoS

If the CoM shifts outside the BoS, the person will likely lose balance and fall unless corrective actions are taken

in dynamic activities, such as walking or running, the CoM moves relative to the BoS, but stability is maintained through adjustments in posture, gait, and movements

to stay balanced, the body makes postural adjustments to ensure that the CoM remains within the BoS. These adjustments involve shifting weight, altering body posture, or adjusting the BoS (e.g., moving feet or changing stance width)

Question 2

Center of Mass (CoM):

Answer 2

The point where the mass of an object or body is concentrated. For the human body, it is typically located just anterior to the sacrum in the pelvis
*S2

It is where the gravitational forces act and is central to the body’s balance

Question 3

Base of Support (BoS):

Answer 3

The area between and including the points of contact with the supporting surface

For a standing person, this is the area defined by the feet. A larger BoS generally provides greater stability

Question 4

Neuromuscular Control:

Answer 4

The nervous system continuously monitors the CoM relative to the BoS and makes rapid adjustments through muscle activation and coordination to maintain balance.

Question 5

Feedback Mechanisms:

Answer 5

Sensory feedback from visual, vestibular, and proprioceptive systems helps the body detect shifts in the CoM and initiate corrective actions to maintain stability.

Question 6

Balance Strategies:

Answer 6

ankle
hip
stepping

Question 7

Ankle Strategy:

Answer 7

Involves small adjustments using the ankles to maintain CoM within the BoS, useful for minor perturbations.

Question 8

Hip Strategy:

Answer 8

Involves larger movements at the hips to maintain balance when the CoM is significantly displaced.

Question 9

Stepping Strategy:

Answer 9

Involves taking a step to enlarge the BoS when the CoM has moved too far outside the BoS to maintain stability.

Question 10

Center of Pressure (CoP):

Answer 10

The point of application of the resultant ground reaction force acting on the body

It is the average location of the vertical forces exerted by the ground through the base of support (BoS)

It represents the point where the pressure is effectively concentrated during standing or dynamic activities

Question 11

CoM vs. CoP:

Answer 11

CoM: Represents the point where the body’s mass is concentrated and where gravity acts.

CoP: Represents where the ground reaction forces are applied. In static conditions, the CoP needs to be within the BoS to maintain balance.

The CoP shifts in response to movements and adjustments to keep the CoM within the BoS.

Question 12

Measuring CoP:

Answer 12

Force Plates: CoP is often measured using force plates, which capture the distribution of forces exerted by the feet and calculate the location of the CoP. This measurement is valuable in assessing balance and postural control.

In clinical settings, CoP measurements can help evaluate balance disorders, the effectiveness of interventions, and the risk of falls.

Question 13

Resources required for postural stability and orientation:

Answer 13

biomechanical constraints

cognitive processing

control of dynamics

orientation in space

sensory strategies

movement strategies

Question 14

biomechanical constraints:

Answer 14

degrees of freedom = number of independent ways a system (like a joint or a body segment) can move

strength = ability of muscles to produce force, essential for generating movement and maintaining posture

limits of stability = boundaries within which the body can maintain balance without changing its base of support (like stepping or reaching)
> distance a person can lean or shift their center of mass while maintaining balance

Question 15

cognitive processing:

Answer 15

attention = Effective postural control requires cognitive resources to monitor and adjust posture. Attention to body position and environmental changes is necessary for balance maintenance

learning = The ability to recall and apply learned strategies for maintaining balance and orientation is essential, especially in novel or challenging situation

Question 16

control of dynamics:

Answer 16

gait = Gait is a dynamic process that involves the coordination of muscles, joints, and sensory feedback to maintain balance and propel the body forward

proactive = body’s ability to anticipate and prepare for changes in movement based on previous experience or environmental cues
> body uses sensory input (vision, proprioception) to predict obstacles or changes in terrain, and adjusts movements accordingly before encountering them

Question 17

orientation in space:

Answer 17

perception = involves integrating sensory input from multiple systems, including vision, the vestibular system (inner ear), and proprioception (sensory feedback from muscles and joints)

gravity, surfaces, vision = estibular system, specifically the otolith organs in the inner ear, detects changes in head position relative to gravity

> Proprioceptive feedback from the body and contact with surfaces (such as the ground) informs the brain about how the body interacts with the environment

verticality = perception of uprightness and alignment with respect to gravity

Question 18

sensory strategies:

Answer 18

sensory integration = brain’s ability to combine information from different sensory systems—vision, vestibular (inner ear), and somatosensory (proprioception and touch)—to form a coherent understanding of the body’s position and movement in space

sensory reweighting = body’s ability to adjust the relative importance of different sensory inputs based on the situation or the reliability of the available information
> when walking in the dark, visual input becomes unreliable, so the brain “reweights” the sensory inputs, relying more on proprioception and vestibular information

Question 19

movement strategies:

Answer 19

reactive = automatic responses that occur after a disturbance or loss of balance
> ankle, hip, stepping

anticipatory = pre-programmed movements that occur before a voluntary action or an expected disturbance, allowing the body to prepare for potential challenges to balance
> important for smooth, coordinated movement and preventing falls during tasks that require planning, like reaching for something on a high shel

voluntary = conscious, intentional movements aimed at accomplishing a specific task, such as walking, reaching, or changing posture
> controlled by higher brain centers and are goal-directed, allowing flexibility and adaptability in complex environments

Question 20

Postural control- involves multiple systems = postural control system

Answer 20

1) Sensory Systems:
-vision’
-vestibular
-proprioception
-exteroception

2) Sensory Integration and Weighting

3) Brain Areas Involved in Postural Control
- Pre-frontal Cortex
- Primary Motor Cortex
- Frontal and Pre-motor Cortex
- Cerebellum
- Brainstem

4) Pathways
- Dorsal
- Ventral

5) Motor response = body generates a motor response (e.g., adjusting posture or movement) to maintain stability

Question 21

Ventral pathway =

Answer 21

“WHAT” Pathway

involved in object identification and recognition, helping us understand what we are looking at

processes information related to the form, color, and details of objects

starts in the occipital lobe (where visual information first arrives) and travels to the temporal lobe, an area associated with recognition of objects, faces, and scenes

It answers questions like:
“What is this object?”
“Is this familiar to me?”
“What are the object’s characteristics (color, texture, shape)?”

Question 22

Dorsal pathway =

Answer 22

“WHERE” Pathway

involved in spatial awareness, helping us determine where objects are in relation to ourselves and guiding our movements

starts in the occipital lobe and moves towards the parietal lobe, an area involved in processing spatial location and motion

It answers questions like:
“Where is this object located?”
“Is it moving? In what direction?”
“How can I interact with it (e.g., reaching, grasping)?”

Question 23

Dorsal Pathway to Posterior Parietal Cortex:

Answer 23

Supports spatial awareness and attention, allowing the body to understand “where” it is in space

Question 24

Ventral Pathway to Inferotemporal Cortex:

Answer 24

Involved in object recognition and identification, processing “what” is in the environment

Question 25

Vision:

Answer 25

Provides visual input about the environment, helping the body understand its position relative to objects and surroundings

Question 26

Vestibular System:

Answer 26

Located in the inner ear, it helps detect changes in head position, motion, and orientation relative to gravity

Question 27

Proprioception:

Answer 27

Involves the sensory feedback from muscles, joints, and tendons, giving the body awareness of its position in space

Question 28

Exteroception:

Answer 28

Provides information from external sensory receptors in the skin, contributing to the awareness of environmental contact (such as pressure or texture from the ground)

Question 29

Pre-frontal Cortex:

Answer 29

Involved in decision-making and planning movements

Question 30

Primary Motor Cortex:

Answer 30

Responsible for the execution of voluntary motor movements

Question 31

Frontal and Pre-motor Cortex:

Answer 31

Involved in the planning and initiation of movement

Question 32

Cerebellum:

Answer 32

Coordinates timing and precision of movements and fine-tunes motor responses

Question 33

Brainstem:

Answer 33

Regulates automatic postural responses and integrates sensory and motor signals

Question 34

Sensory Signals:

Answer 34

Sources: Visual, vestibular, auditory, proprioception, touch, and visceral systems provide sensory feedback to the brain about the body’s position and movement relative to its environment. Proprioceptive and Skin Afferents: These signals convey information from the body's joints, muscles, and skin, helping the central nervous system understand its spatial orientation and posture.

Question 35

Basal Ganglia:

Answer 35

Central to motor control, the basal ganglia play a major role in initiating and regulating voluntary movements. It processes sensory input and sends signals to the cerebral cortex and other brain areas to refine motor actions. Dopamine from the basal ganglia affects movement regulation.

Question 36

Cerebral Cortex:

Answer 36

The cognitive reference is represented by the cerebral cortex, which governs voluntary movements and cognitive processes involved in postural adjustments. The cortex integrates sensory feedback and decision-making processes, which are essential for initiating and modifying movements.

Question 37

Thalamus:

Answer 37

Serves as a relay station, transmitting sensory signals (e.g., proprioceptive feedback) to the cortex for processing and integrating them with motor commands.

Question 38

Limbic System:

Answer 38

The emotional reference is represented by the limbic system, which influences emotional motor behavior. Emotional states can directly affect posture and movement, integrating emotional responses with motor control.

Question 39

Automatic Processes:

Answer 39

Midbrain, Pons, Medulla: These areas are involved in automatic postural adjustments and reflexive movements. The cerebellum fine-tunes movements and coordinates balance. Spinal Cord & Central Pattern Generators (CPGs): The spinal cord houses CPGs, which control rhythmic movements such as walking. These generators help maintain automatic locomotion without conscious effort, regulated by sensory feedback and brain input.

Question 40

Spinal Locomotor Network:

Answer 40

Involved in automatic and rhythmic movements, the spinal locomotor network is essential for walking and maintaining posture, allowing for dynamic adjustments based on proprioceptive and sensory feedback.

Question 41

Motor Outputs:

Answer 41

Automatic Movements: Controlled by subcortical structures (brainstem, cerebellum, spinal cord), these involve reflexive and rhythmic activities, like maintaining posture while standing or walking. Voluntary Movements: Controlled by the cerebral cortex and basal ganglia, voluntary actions are goal-directed and consciously initiated, such as deciding to change posture or walking toward an object.

Question 42

Postural control in Stroke

Answer 42

83% of pts. 2-4 wks post stroke -> balance disability Motor control impairments (caused by reduction in # and firing rate of motor units): slow movements, weakness, fatigue, incoordination, decreased force production, co-contractions

Question 43

Reduction in the Number and Firing Rate of Motor Units:

Answer 43

Damage to the brain affects the recruitment and activation of motor units, which are responsible for muscle contraction.

Question 44

Slow Movements (Bradykinesia):

Answer 44

Movements become slower due to a reduced ability to activate muscles rapidly. This can limit the speed and efficiency of postural adjustments.

Question 45

Weakness (Paresis):

Answer 45

Muscle weakness is a hallmark of stroke, particularly on one side of the body (hemiparesis), and is associated with reduced muscle strength and endurance, contributing to postural instability.

Question 46

Fatigue:

Answer 46

Stroke patients often experience physical and mental fatigue, which further impairs their ability to maintain posture, particularly during prolonged activities.

Question 47

Incoordination:

Answer 47

Loss of motor coordination results in jerky or uncoordinated movements, impairing the ability to execute smooth postural adjustments and movements.

Question 48

Decreased Force Production:

Answer 48

Muscles affected by the stroke produce less force, making it difficult to perform actions that require strength, such as standing, walking, or reaching.

Question 49

Co-contractions:

Answer 49

In some cases, there is excessive co-activation of antagonist muscles, resulting in stiff and inefficient movements, which hinder smooth postural adjustments.

Question 50

Postural Control Challenges Post-Stroke:

Answer 50

Asymmetry in Weight Distribution Delayed Postural Responses Impaired Anticipatory Postural Adjustments (APAs) Sensory Deficits Poor Coordination of Balance Strategies

Question 51

Asymmetry in Weight Distribution:

Answer 51

Stroke patients often exhibit uneven weight-bearing, with a tendency to shift weight towards the non-affected side. This asymmetry affects balance and stability.

Question 52

Delayed Postural Responses:

Answer 52

Normally, the body reacts quickly to maintain balance when perturbed, but stroke patients often exhibit delayed and weaker postural responses, increasing the risk of falls.

Question 53

Impaired Anticipatory Postural Adjustments (APAs):

Answer 53

Stroke can affect the ability to prepare the body for upcoming movements, such as shifting weight before stepping. This impairment can lead to instability and falls during voluntary actions.

Question 54

Sensory Deficits:

Answer 54

Stroke may impair proprioception and other sensory feedback mechanisms, making it difficult for patients to detect changes in body position and adjust accordingly.

Question 55

Poor Coordination of Balance Strategies:

Answer 55

Stroke affects the ability to utilize balance strategies effectively, such as ankle, hip, and stepping strategies that help maintain upright posture in response to perturbations.

Question 56

what leads to the decrease in speed?

Answer 56

decrease number of FT MUs and increase atrophy of type 2 fibers -> slower muscle contractile properties

Question 57

what leads to the decrease in strength?

Answer 57

decrease supraspinal drive and increase recurrent inhibition -> slower MU firing rates

Question 58

what leads to the decrease in precision?

Answer 58

increase co-contraction and decrease coordination -> reduced net force

Question 59

fast twitch =

Answer 59

type 2 fibers

Question 60

slow twitch =

Answer 60

type 1 fibers

Question 61

EMG recordings during a single squat in a subject 1-month post-stroke (right) and a healthy age- and sex-matched control (left)

Answer 61

Delayed activation in terms of anticipatory of key muscles in healthy adults - delayed timing and reduced activation of other muscles Stroke: quite different acceleration pattern - anterior tip fires before the squat - to set up firing before you go - non paretic leg overshoots - paretic doesn’t go Deceleration phase -less amplitude and delayed firing Healthy: pretty symmetrical acceleration pattern Deceleration phase - both quads and hamstrings fire at similar time

Question 62

Postural control in Stroke 3 global impairments in balance:

Answer 62

sensation (to detect or anticipate postural disturbance) neural processing (to select appropriate feedback/feedforward postural control) effective motor output

Question 63

sensation:

Answer 63

Impairment: Stroke can affect sensory pathways, leading to reduced ability to detect or anticipate postural disturbances This can include deficits in proprioception (awareness of body position), vestibular function (sense of spatial orientation), and somatosensation (sense of touch and pressure) Difficulty in perceiving shifts in body position or external forces can impair the ability to make timely adjustments to maintain balance

Question 64

Neural Processing:

Answer 64

Impairment: Stroke can disrupt the brain's ability to process sensory information and select appropriate feedback or feedforward mechanisms for postural control This includes issues with integrating sensory inputs and generating appropriate motor responses Ineffective neural processing can result in poor decision-making regarding postural adjustments, leading to unstable or inappropriate responses to balance challenges

Question 65

Effective Motor Output:

Answer 65

Impairment: Motor output can be compromised due to weakened or impaired muscle activation and coordination This affects the ability to execute and adjust motor responses required for maintaining balance Reduced strength, coordination, and control over movement can lead to difficulties in maintaining posture and responding to perturbations, increasing the risk of falls

Question 66

Impairment to the timing, magnitude and sequencing of muscle activation:

Answer 66

Timing of Muscle Activation: disrupt the neural pathways responsible for coordinating the precise timing of muscle contractions > can result in delayed or premature muscle activation during movements Magnitude of Muscle Activation: can affect the ability to generate sufficient force in the muscles > due to weakened muscle strength or reduced motor control Sequencing of Muscle Activation: involves the correct order of muscle activation for coordinated movements > disrupt this sequence = leading to improper muscle activation patterns

Question 67

Delayed muscle activation can lead to:

Answer 67

difficulty in responding quickly to balance disturbances or changes in posture Premature activation might cause instability or excessive muscle tension, both of which can affect overall balance and movement efficiency

Question 68

Inadequate muscle activation magnitude can result in:

Answer 68

insufficient support for maintaining posture or performing movements can make it challenging to maintain balance, especially during dynamic tasks or when faced with unexpected perturbations

Question 69

Incorrect sequencing can lead to:

Answer 69

inefficient or uncoordinated movements might cause a person to rely excessively on certain muscle groups while neglecting others, leading to poor balance and increased risk of falls

Question 70

Rehabilitation Strategies: timing

Answer 70

Use exercises that focus on improving the timing of muscle activation This might include tasks that require rapid adjustments to changing conditions or feedback-based training to help the patient react more promptly to balance challenges.

Question 71

Rehabilitation Strategies: magnitude

Answer 71

Implement resistance training and functional exercises to increase muscle strength and improve the ability to generate adequate force Tailor exercises to address specific muscle groups that are weakened or underperforming.

Question 72

Rehabilitation Strategies: sequencing

Answer 72

Incorporate coordination and motor control exercises that emphasize proper sequencing of muscle activation Use tasks that mimic functional movements and gradually increase complexity to enhance sequencing accuracy.

Question 73

Postural control in PD

Answer 73

As Parkinson's disease advances, there is a progressive loss of postural stability, which contributes to an increased risk of falls = motor and sensory system impairments affecting the ability to maintain and adjust posture Gait abnormalities such as shuffling, reduced arm swing, and difficulty initiating or stopping movement are common = gait dysfunction Postural instability less responsive to drug therapy Up to 68% falls in later stages of ds Lack of balance reaction, flexed posture, decreased trunk rotation, difficulty executing simultaneous movements/sequential movements

Question 74

Forward-Flexed Posture in Parkinson's Disease:

Answer 74

shifts the body's center of gravity forward shift makes it more challenging to maintain balance, particularly during dynamic movements or when responding to external perturbations

Question 75

Basal Ganglia =

Answer 75

controlling the flexibility of postural tone scaling up the magnitude of postural movements = regulating how much muscle activation is needed to maintain or correct posture selecting postural strategies for environmental context automatizing postural responses and gait = more deliberate, effortful, and less fluid movements

Question 76

Progression of PD

Answer 76

mobility -> bradykinesia and rigidity kinesthesia problems -> freezing decline in executive function -> inflexible set

Question 77

non-motor symptoms:

Answer 77

cognitive processing - attention -learning

Question 78

rigidity:

Answer 78

biomechanical constraints: - degrees of freedom - strength - limits of stability

Question 79

bradykinesia:

Answer 79

control of dynamics - gait - proactive movement strategies - reactive - anticipatory - voluntary sensory strategies - sensory integration - sensory reweighting

Question 80

proprioception deficits:

Answer 80

control of dynamics - gait - proactive

Question 81

Healthy adults stand up on force plate and PD pts:

Answer 81

Diff direction perturbations Solid black line - healthy adults = cone of stability - big Stooped posture - decreased stability margin especially with backward stability area PD - especially small stability margin - especially backward PD patients on force plate - look at COP trajectory and postural sway (resting)

a good way of sway - instability front to back > On DBS - it reduces postural sway > On L DOPA - NOT ALWAYS - but in general doesn’t help postural control > On DBS and LDOPA - decreases some but still isn’t great

Question 82

Postural control in mTBI

Answer 82

Balance disorders- one of the most common symptom 23-81% report dizziness Postural instability due to dysfunction in sensory integration Deficits in cognition -> attention affects postural control

Question 83

In mild traumatic brain injury (mTBI), also known as a concussion, postural control can be significantly affected

Answer 83

balance issues such as dizziness, unsteadiness, and difficulty maintaining equilibrium = result from disruptions in the vestibular, visual, or proprioceptive systems ability to process sensory information from the environment and the body = lead to difficulties in integrating visual, vestibular, and proprioceptive inputs necessary for maintaining balance ability to coordinate and execute postural adjustments may be compromised may experience slower reaction times, affecting their ability to respond quickly to sudden changes in posture or balance

Question 84

concussion:

Answer 84

traumatic brain injury that changes the way your brain functions brain is made up of soft tissue and is protected by blood and spinal fluid - when skull is jolted too fast or is impacted by something - brain shifts and hits against the skull can lead to bruising and swelling of brain, tearing of blood vessels and injury to nerves, causing concussion most concussions are mild and can be treated with appropriate care - but left untreated, it can be deadly

Question 85

Reaction time affects postural stability and righting reactions =

Answer 85

Reaction time affects postural stability and righting reactions *those with TBI or concussion = slower reaction time delayed response to sudden shifts or disturbances in their posture challenging to adapt to changing conditions quickly, leading to instability Righting reactions = automatic adjustments to maintain an upright position, can be delayed > impacting the individual's ability to recover from perturbations and maintain an upright posture

Question 86

Postural control in MS

Answer 86

Due to extensive damage to CNS Demyelination -> sensorimotor cortex, basal ganglia, cerebellum, spinal pathways Motor learning preserved in early phase of MS -> capacity dependent on severity While motor learning—especially the ability to adapt and acquire new motor skills—may remain preserved in the early stages of MS, the capacity for motor recovery and learning is highly dependent on the severity of CNS damage

Question 87

MS disease progresses =

Answer 87

postural control can become increasingly impaired, potentially leading to issues such as unsteady gait, increased risk of falls, and difficulty in performing coordinated movements Capacity to improve postural control depends on severity of disease

Question 88

Critical deficit: slowed spinal SS conduction ->

Answer 88

delayed postural latencies and increased postural sway Postural sway - good with eyes open - not closed *with MS *exacerbated swaying with eyes closed Not switching to the lead - still lagging *not kicking in optimally *demyelination - nerves cant carry info fast Patients often demonstrate better stability with their eyes open, but closing the eyes exacerbates swaying because they rely more heavily on the remaining sensory systems (like vision) to compensate for impaired proprioception and vestibular input delayed response, or the inability to "switch to the lead," occurs because demyelinated nerves cannot carry information quickly enough. As a result, the body's postural adjustments lag, leading to less optimal balance control

Question 89

Postural Control in SCI

Answer 89

Aberrant (or absent) synapse formation leads to inappropriate muscle recruitment and poor coordination Changes in excitability of spinal locomotor networks render some synapses hyperexcitable and some hypoexcitable Chronic SCI -> progressive deterioration of muscle properties diminishes the ability to generate movements No consistent superspinal drive Lots of muscle changes *Further diminishes the ability 
of muscles to generate moment

Question 90

study by Jorgensen et al., published in Spinal Cord, focuses on assessing unsupported sitting in patients with spinal cord injury (SCI):

Answer 90

assessment of unsupported sitting in SCI patients was reliable and valid when modified from stroke-specific scales individuals with incomplete spinal cord injury (SCI) were found to have better unsupported sitting balance compared to those with complete SCI Higher scores = better sitting balance *lower injuries = more core muscle control to be able to sit ASIA A L1 - good balance T10 ASIA C Could look very diff. Lots of variability in
incomplete ASIA
cases Greater total sway and postural sway than those without SCI

Question 91

Vestibular system roles:

Answer 91

Perception of body position and self-motion = helps sense movement and orientation in space Orientation of trunk to vertical = ensures that the body is aligned with gravity Controls COM (postural reactions) = triggers postural reactions to maintain stability Stabilize head in space = keeps the head stable in space, especially during movement, aiding in clear vision and balance

Question 92

Acute onset of vestibular symptoms = can be huge

Answer 92

often indicate sudden dysfunction in the vestibular system severe dizziness, vertigo, imbalance, nausea, or difficulty stabilizing vision can lead to major disruptions in daily activities and postural control may be related to various causes, such as vestibular neuritis, labyrinthitis, or even more serious conditions like strokes

Question 93

postural control in patients with bilateral vestibular failure (BVF)

Answer 93

BVF patients exhibit significant postural instability, especially when deprived of visual or proprioceptive feedback Postural sway is increased in BVF patients, especially with eyes closed - Visual feedback helps compensate for vestibular loss, making sway comparable to healthy controls when eyes are open When proprioceptive feedback is reduced (e.g., standing on foam), BVF patients show greater instability, even with visual input Vestibular input loss destabilizes BVF patients, especially during head movements, but cognitive tasks didn't significantly worsen their balance compared to controls

Question 94

Balance Evaluation: Outcome tools: Stroke*

Answer 94

Berg Balance Scale: MDC = 2.5-8.1 Dynamic Gait Index: MDC = 2.6-4 Functional Reach Test: MDC = 2.3-6.79 Timed "Up & Go": MDC = 2.9s *Highly recommended

Question 95

Other Outcome tools: Stroke

Answer 95

6 min walk test 10 meter walk test Fugl-Meyer (LE) Functional Independence Measure Goal Attainment Scale Motor Activity Log Orpington Prognostic Scale Stroke Impact Scale Stroke Rehabilitation Assessment of Movement—Limb Subscales (STREAM)

Question 96

Balance Evaluation: Outcome tools: PD*

Answer 96

Berg Balance Scale: MDC = 5 Dynamic Gait Index: MDC = 2.9 Functional Gait Assessment: MDC = 4 MiniBesTest: MDC = 5.52 Timed "Up & Go": MDC = 3.5-11s *Highly recommended

Question 97

Other Outcome tools: PD

Answer 97

6 min walk test 10 meter walk test MDS-UPDRS revision Mini Mental Status Exam Montreal Cognitive Assessment PDQ-39 PDQ-8 Timed Sit to Stand, 5 times

Question 98

Balance Evaluation: Outcome tools: mTBI

Answer 98

High Level Mobility Assessment (HiMAT)- MDC = 4 points or decrease of 2 points *Good for concussion - looks at balance - more high functioning people with TBI *No highly recommended

Question 99

Other Outcome tools: mTBI

Answer 99

mTBI (concussion) EDGE currently under development at ANPT TBI EDGE* available Coma Recovery Scale- Revised Moss Attention Rating Scale “Recommended” balance measures include: 6 min walk test, 10 meter walk test, BBS, Community Balance and Mobility Scale

Question 100

Balance Evaluation: Outcome tools: MS*

Answer 100

Berg Balance Scale- MDC =not available Dizziness Handicap Inventory- MDC= 22.50 TUG w/Cognitive & Manual- MDC =not available (dual tasking hard with this population) *Highly recommended

Question 101

Other Outcome tools: MS

Answer 101

12-Item MS Walking scale 6 min walk test 9-hole peg test MS Functional Composite MS Impact Scale-29 MS- QoL 54 Timed 25 ft walk

Question 102

Balance Evaluation: Outcome tools: SCI*

Answer 102

TUG- MDC= 10.8 seconds *Highly recommended

Question 103

Other Outcome tools: SCI

Answer 103

6 min walk test 10 meter walk test ASIA Impairment Scale Hand-Held Myometry Walking Index for SCI II Numeric Pain Rating Scale WHO QoL- BREF

Question 104

Balance Evaluation: Outcome tools: Vestibular Disorders*

Answer 104

Dynamic Gait Index- MDC= 3.2 points Dizziness Handicap Inventory- MDC= 17.18 Functional Gait Assessment- MDC=- 6points *Highly recommended

Question 105

Other Outcome tools: Vestibular Disorders

Answer 105

New call for EDGE task force for revisions Dix-Hallpike

Question 106

Postural Control- Interventions
Balance Rehabilitation Study to measure pre and post intervention stuff

Answer 106

Rate of falls improved after intervention - in intervention group *activating muscles Sooners - reduce rate of falls *didn’t change in control group Latency kicked in sooner to the task after the training = what we want - training anticipatory postural adjustments

Question 107

Healthy older adults: good evidence

Answer 107

dose-response relationships of ”balance training” parameters training period of 11-12 wks frequency of 3x/week 31-45 minutes per session 36-40 total # of sessions Variety of training modalities (commonly multimodal exercise-based balance training)

Question 108

Chronic stroke: good evidence

Answer 108

balance/wt. shifting and gait training effective balance/wt. shifting and gait training effective improve proprioceptive feedback, which is crucial for maintaining balance and coordinating movements Gait training helps improve walking speed, stride length, and overall gait mechanics

Question 109

Parkinson’s Disease: good evidence

Answer 109

exercise interventions probably reduce rate of falls mod intensity PRE 2-3x/wk over 8-10 wks variety of exercise types, including resistance training, balance exercises, and aerobic activities, have been shown to improve balance and mobility, thereby reducing fall risk

Question 110

Multiple Sclerosis: medium evidence

Answer 110

balance interventions have a medium effect on outcomes high intensity* & task-specific interventions are associated with better outcomes interventions include balance training exercises, stability and coordination drills, and exercises targeting specific balance deficits high-intensity interventions often result in greater improvements in strength and endurance compared to moderate or low-intensity exercises

Question 111

Vestibular disorders: medium evidence

Answer 111

moderate evidence for improved postural stability following vestibular rehab exercises

Question 112

mTBI: weak evidence

Answer 112

weak evidence for vestibular rehab exercises, subthreshold aerobic exercise Concussion - weak evidence for subthreshold aerobic exercise in terms of improving BALANCE only *not a lot of RCT on balance training specificily

Question 113

Incomplete SCI: weak evidence

Answer 113

weak evidence for BWST (+ stimulation – FES or tDCS), small scale studies on VR-based balance training show promise Incomplete SCI - weak evidence -FCS to muscle or tDCS to brain

Question 114

*Reminder: Key Components of Postural Control

Answer 114

1) biomechanical constraints 2) stability limits/verticality 3) anticipatory postural adjustments 4) postural responses 5) sensory orientation 6) stability in gait

Question 115

biomechanical issue example: ankle strength/ROM

Answer 115

Weakness in the muscles surrounding the ankle, particularly the dorsiflexors (muscles that lift the foot) and plantarflexors (muscles that point the toes) poor control of foot movement, increased risk of tripping or falling, difficulty with activities like walking uphill or climbing stairs, and general instability

Question 116

stability limits example: reaching

Answer 116

When reaching, the body's center of mass shifts towards the direction of the reach. This shift can challenge balance and stability. area within which the body’s weight is supported by the contact with the ground (e.g., feet). As one reaches, the base of support effectively becomes narrower, increasing the risk of losing balance Reaching further requires greater control and stability

Question 117

anticipatory postural adjustments example: planned change of position

Answer 117

Before the person begins to stand, muscles are activated to stabilize the body and prepare for the shift in weight. This includes activating the muscles of the trunk (e.g., abdominal muscles and erector spinae) and lower extremities (e.g., quadriceps and gluteals pre-activation helps to counteract the forward shift of the center of mass that occurs when moving from a seated to a standing position person may lean slightly forward or shift their body weight towards their feet before initiating the standing motion. This movement helps to align the center of mass over the base of support (the feet) to prepare for the lifting action

Question 118

Reactive responses example: unplanned response - step

Answer 118

person perceives the loss of balance, often through sensory feedback from their feet and proprioceptors, indicating that they are tilting or shifting unexpectedly Early detection of the disturbance allows for a faster and more effective reactive response person quickly initiates a step to regain balance. This step is typically a rapid and unplanned movement designed to adjust the base of support and realign the center of mass over the feet By stepping in the direction of the disturbance, the individual expands their base of support and shifts their center of mass back within a stable zone By stepping in the direction of the disturbance, the individual expands their base of support and shifts their center of mass back within a stable zone

Question 119

sensory orientation example: impact of vision/vestibular system

Answer 119

In a busy environment, visual input helps the person navigate around obstacles and maintain awareness of their surroundings vestibular system works to stabilize the visual field by adjusting head and eye movements. In dynamic environments, it helps maintain balance by sensing changes in head position and motion If a person with impaired vision (e.g., due to cataracts or blurred vision) tries to walk down the street, they may struggle to detect moving objects or judge distances correctly, increasing the risk of collisions or falls

Question 120

gait example: change gait speed or direction or cognitive load

Answer 120

Walking at an increased pace requires the person to take quicker steps and increase stride frequency = Faster gait speed challenges balance control and requires greater coordination and muscle strength Walking at a reduced pace involves longer steps and a slower cadence = Slower gait speed can improve stability and reduce the risk of falls but might be associated with reduced momentum and difficulty in navigating certain obstacles