Upright Balance

What risks are associated with balance deficits?

falls, reinjuries, new injuries

what is postural control synonymous with?

balance

control of the body’s position in space for the purposes of orientation and stability

postural control

relationship between body segments and the body and environment

postural orientation

control of center of mass relative to base of support; active resistance to external forces on the body

postural stability/equilibrium

point at the center of the total body mass

center of mass

area of the body that is in contact with the support surface

base of support

center of the distribution of the total force applied to the supporting surface

center of pressure

2 primary mechanisms for balance in the context of motor control

feedforward control, feedback control

balance is a ______________

continuum

is there variability in normal balance?

yes

is stance ever completely static? why?

no, there is a small imperceptible sway even in healthy individuals

are automatic responses reflexes?

no, they are responses which are slower

what are automatic postural responses?

reactive mechanisms (feedback control) that respond to unexpected perturbations

what is the order of muscle activation in ankle strategies?

distal to proximal

when are ankle strategies employed first?

anterioposterior perturbations, on firmer surfaces with smaller perturbations

what is the order of muscle activation in hip strategies?

proximal muscles activated first

when are hip strategies employed first?

mediolateral perturbations, narrow BOS, compliant surfaces, large/fast perturbations

what strategies are used to recover multidirectional instability (when ankle or hip strategies alone are insufficient

muscle synergies

use prior knowledge of task, environment, and individual constraints, to stabilize and orient body for voluntary movement

anticipatory postural adjustements

what is the predominant sensation engaged in static standing (70%)

somatosensation

what 3 senses are involved in static standing, from most to least

somatosensation, vestibular, vision

a central representation of the body and its environment

body schema

does vision have a greater role in proactive or reactive responses? why?

proactive, slower neural conduction

when is the vestibular system engaged most?

unstable surfaces and head movements

examination approach using manipulation/reweighing of sensory input

sway referencing

what cognitive processes can influence balance control?

dual task capacity, fear, executive function, motivation, self efficacy

is there a designated balance control center of the brain?

no

what areas of the brain are involved in balance

spinal cord, brain stem, cerebellum, basal ganglia, cerebral cortex

what part of the brain is responsible for adaption to sudden task changes?

basal ganglia

important parts of the brain for integrating sensory inputs

brain stem and cerebellum