Postural Control

The postural system takes into account what body systems?

-musculoskeletal

-muscle synergies

-sensory systems

-sensory organization

-cognitive strategies

-cognitive resources

What are the strategies that are underlying postural control?

-motor strategies

-sensory strategies

-sensorimotor strategies

-attentional strategies

Describe how motor strategies underlie postural control

organizes movements that are appropriate for controlling the body's position in space

Describe how sensory strategies underlie postural control

organizes sensory info from visual, somatosensory, and vestibular systems to promote postural control

Describe how sensorimotor strategies underlie postural control

reflects the rules for coordinating sensory and motor aspects of postural control

Describe how attentional strategies underlie postural control

determines the degree of attentional given to a postural task when performing other tasks simultaneously

What are the most important neural subsystems that contribute to the control of postural orientation and stability?

-cerebellum

-basal ganglia

-thalamus

-hippocampus

-interior parietal cortex

-frontal lobe

Is feed forward or feedback used with an expected postural disturbance?

feed forwarrd

Is feed forward or feedback used with an unexpected postural disturbance?

feed back

T or F: No one can stand absolutely still

True -- body constantly sways in small amounts (usually backward and forward)

What are better labels for "static" balance?

-quiet stance

-steady state balance

Steady state balance takes into consideration what 4 things?

-alignment

-muscle tone

-postural tone

-movement strategies

What are the strategies to maintain anteroposterior stability

1) ankle

2) hip

3) stepping / change in support

What defines muscle synergies?

characteristic patterns of muscle activity

During a small forward sway, what muscles are utilized to maintain anteroposterior stability? What strategy?

paraspinals, hamstrings, gastroc

ankle strategy

During a small backward sway, what muscles are utilized to maintain anteroposterior stability? What strrategy?

abdominals, quads, tib anterior

ankle strategy

During a big forward sway, what muscles are utilized to maintain anteroposterior stability? What strategy?

quads, abdominals

hip strategy

During a large backward sway what muscles are utilized to maintain anteroposterior stability? What strategy?

hamstrings, paraspinals

hip strategy

Which movement strategy would you expect to see with standing in tandem on a curb?

hip strategy

Which movement strategy would you expect to see with standing on a firm surface with a small nudge to your back?

hip strategy

Which movement strategy would you expect to see with standing as a large dog pounces on your chest

stepping / change in support

Which movement strategy would you expect to see with standing on a soft, uneven surface?

ankle

Mediolateral strategies primarily use what type of strategies to maintain stability?

hip and trunk

T or F: The knees are important joint for maintaining mediolateral stability

False

Lateral pertubation primarily activate what muscles?

rectus femoris and TFL

Why do alternative strategies need to be used to recover stability in medioalteral or diagonal directions?

due to alignment of body segments and muscles requiring activation of forces at different joints and in diff directions to recover

T or F: Muscles in the legs and trunk, besides the rectus femoris and the TFL, tend to remain inactive with diagonal pertubations

False; these muscles will activate with diagonal pertubations

How does multidirectional stability occur in regard to reactive postural control?

-blend of response patterns

-controls stability in 360deg continuum of possible perturbation directions

T or F: A muscle can belong to one or more synergy in regard to reactive balance

True

Do postural motor strategies use feedback or feedforward in standing? What about sitting?

they use both in standing & sitting

What types of activities are used by a PT to train reactive motor strategies with older adults?

perturbations to simulate a crowded space, dog jumping up, etc...

-utilizing real-life scenarios they may face

What types of activities are used by a PT to train reactive motor strategies with children?

using a physioball, play-based activities, or other types of un-even surfaces

What types of activities are used by a PT to train reactive motor strategies with athlets?

high level sport based perturbations, uneven surfaces, etc

Anticipatory balance control is AKA what?

proactive balance control

How does proactive balance control occur?

-CNS pre-tunes perceptions based on prior experience

-repeated exposure to a given task causes the pt to refine their response to optimize efficiency

How do pts without neural pathology learn anticipatory balance control?

with repeated exposure, can shift from one postural movement strategy to another to optimize response efficiency

T or F: Anticipatory postural adjustment adapts to changnig task & environment in both sitting and standing

True

What does APA stand for?

anticipatory postural adjustment

What types of training activities are used by a PT to train proactive motor strategies with older adults?

-reaching for something while standing

-catching something

What types of training activities are used by a PT to train proactive motor strategies with athletes?

-catching / throwing ball

-changing BOS in diff situations

What type of balance is an essential part of voluntary movements that are potentially destabilizing?

proactive balance

Reaching and lifting tasks are part of what type of balance?

A) reactive balance

B) steady state balance

C) proactive balance

D) NOT balance

C) proactive

What systems provide frame of reference for the CNS to organize specific sensory information in regard to postural control?

1) visual

2) somatosensory

3) vestibular

How does vision contribute to postural control?

-gives info about position & motion of head with respect to surrounding objects

-reference for verticality

T or F: Vision is needed to maintain postural control

False (don't need vision to stand in dark room or with eyes closed)

T or F: Vision is not always correct about exogcentric and egocentric motion

True

What is egocentric vs exocentric motion?

egocentric = self motion

exocentric = object motion

T or F: Vision is not necessary to maintain postural control, but it influences balance

True

What are the somatosensory contributions to postural control?

-provides CNS with position and motion info about body with reference to supporting surfaces

-info about relationship of body segments to one another

-movement of body with respect to a fixed horizontal surface

T or F: Somatosensory system is responsible to body movement in respect to a vertical surface while vision is in respect to a horizontal surface

False; vise versa

T or F: Somatosensory info is not appropriate for vertical orientation on a moving (boat) or a non-horizontal surface (ramp)

True

What are the vestibular contributions to postural control?

-info about position and movement of head in respect to gravity and intiial forces

-cannot distinguish between head movement on body (nodding) vs head with body movement (forward bending)

T or F: The vestibular system can differentiate between a head nod and fully bending over to touch toes

False

What are the 6 conditions that are tested using the CTSIB?

1) firm, EO

2) firm, EC

3) firm, vision conflict

4) foam ,EO

5) foam, EC

6) fam, vision conflict

What is the SOT? Describe it

sensory organization testing

-computerized approach to investigate how the CNS adapts to multiple sensory inputs using a moving platform & visual surround

-movement is sway-referenced

What are the 6 conditions of the SOT?

1) fixed, EO

2) fixed, EC

3) fixed, EO with moving visual surround

4) moving surface, EO

5) moving surface, EC

6) moving surface, EO, moving visual surround

What systems are accurate in the 6 SOT conditions?

1) all systems

2) vestib, somato

3) vestib, somato

4) vestib, vision

5) vestib

6) vestib

What systems are INACCURATE in the 6 SOT conditions?

1) none

2) none

3) vision

4) somato

5) somato

6) vision & somato

In the conditions that eyes are closed for the CTSIB and the SOT, is the vision system inaccurate? why?

NO not inaccurate, just not utilized! only in the SOT is vision inaccurate when the surrounding area is moving (conditions 3 & 6)

If a pt has a visual dependence with balance, they will have problems with what conditions during the SOT?

2, 3, 5, 6

If a pt has a somatosensory dependence with balance, they will have problems with what conditions during the SOT?

4, 5, 6

If a pt has vestibular dysfunction, they will have problems with what conditions during the SOT?

5 & 6

What is sensory reweighting?

when the CNS reweights the use of sensory information to maintain balance if one sense is inaccurate or absent

In early recovery, postural control relies on what?

visual inputs

As motor skill is re-gained during recovery, a pt may reweight from visual inputs to utilize what?

somatosensory inputs

Is somatosensory or visual info faster for responding to surface translation for reactive balance?

somatosensory

The CNS relies on what when rapid displacements happen on a support surface?

relies on the somatosensory inputs

When the support surface is displaced horizontally, what system plays a minor role?

vestibular system plays a minor role in recovering postural stability

What input is most important for proactive balance? Why?

visual because it provides critical info about the nature of the task and environment to determine APAs needed to maintain stability

What should be used to assess the integrity of sensory systems for balance control?

CTSIB or SOT

If a sensory input is permanently lost, what should be done in regard to PT training for balance?

training should promote reweighting to reply on alternative senses

T or F: Attentional demands to postural control increase when dual tasks are introduced

True

What cognitive things come into place that may affect postural control

anxiety & fear of falling

T or F: Adding an additional task during balance training will jhave a detrimental effect on postural stability

True

T or F: You should assess and treat balance under only a single-task condition, and not challenge with a dual-task condition as it has detrimental effects on balance

False! assess and train both!!