Motor Control: Postural Stability

What is postural stability

maintaining COM within BOS

What is postural orientation

maintaining body alignment and gaze relative to task and environment

What is postural tone

baseline muscle activity that prepares the body for movement

What determines postural control strategies

task specify (depends on goal and context)

What is Goal #1 of postural stability

COM within BOS

What is proactive (anticipatory) control?

planning for expected disturbances to stability

What is reactive control

responding to unexpected disturbances

What are automatic postural reactions (APR)

reflexive responses to restore balance

What are volitional postural corrections

conscious adjustments to override or modify automatic responses

What is steady-state control

maintaining posture in stable, predictable conditions

What are the four automatic postural strategies

Ankle strategy

Hip strategy

Suspensory strategy

Stepping strategy

What does vision contribute to posture

orientation and movement via optic flow

What does the vestibular system detect

body orientation relative to gravity

What does somatosensation detect

COM position and displacement

What is the role of the spinal cord in balance

antigravity support

What is the role of the brainstem in balance

automatic postural responses

What is the role of the cerebellum in balance

adjusts response magnitude (gain)

What is the role of the basal ganglia in balance

selects appropriate response

What is the role of the cortex in balance

prediction and intention

What is the role of the limbic system in balance

emotional influence on posture

What is goal #2 in posture

postural alignment and gaze stabilization

What are postural alignment reflexes

automatic adjustments that support task performance

Are alignment reflexes feedforward or feedback

both (planned and sensory driven)

What is the vestibulo-ocular reflex

keeps vision stable during head movement

What is the vestibulospinal reflex

adjusts trunk posture via antigravity muscles

The vestibulospinal reflex is controlled by what spinal tract

lateral vestibulospinal tract

What is the vestibulocollic reflex?

stabilizaes head via neck muscles

The vestibulocollic reflex is controlled by what spinal tract

medial vestibulospinal tract

What does the lateral vestibular nucleus do

activates antigravity muscles for balance

What does the medial vestibular nucleus do

adjusts head position

What is the medial longitudinal fasciciulus (MLF)

coordinates eye and head movement

Role of vestibulocerebellum

controls VOR, eye movements, balance

Role of spinocerebellum

internal model of posure

Role of temporoparietal cortex

perception of body verticality

What is pusher syndrome

patient pushes away from midline

What is goal #3 in posture

postural tone

What does teh reticular formation do

regulates muscle tone

what nuclei help facilitate muscle tone

ceruleus and raphe nuclei

What nuclei helps inhibit muscle tone

predunculopontine

role of cerebellum in tone

adjusts muscle spindle sensitivity (gain)

role of basal ganglia in tone

modulates tone via PPN

The pontine reticulospinal tract facilitates

extensors

The medullary reticulospinal tract facilitates

flexors