balance theory and assessment

Question 1

what is centre of gravity?

Answer 1

-the point about which the mass of all body segments is evenly distributed

Question 1

what is newtons first law?

Answer 1

-the body is in a state of equilibrium when the projection of its centre of gravity ir centre of mass (COG) falls within its base of support

Question 2

what is the base of support (BOS)?

Answer 2

the surface area of the part which is involved in the support of the object

Question 3

when is balance achieved - in relation to the BOS and COM/COG?

Answer 3

Balance is achieved when the COM falls inside the BOS

Question 4

what is important for postural control of standing balance?

Answer 4

-body alignment
-muscle tone - background muscle tone

Question 5

what is postural sway?

Answer 5

a term used to describe the unconscious, small movements that happen around the body’s center of gravity in order to maintain balance.

Question 6

why does postural sway happen?

Answer 6

-2/3 of our body mass is located 2 thirds of body height above the ground
-major challenge to our control system
-allows pressure to be distributed across larger SA on the feet (ie prevents single pressure point)

Question 7

what is postural control?

Answer 7

the act of maintaining, achieving or restoring a state of balance during any posture or activity

Question 8

define static balance

Answer 8

the maintenance of a specified posture

Question 9

define dynamic balance

Answer 9

-voluntary mvt
-reaction to an external disturbance such as a trip, a slip or a push

Question 10

what 3 input ‘ systems’ does our brain receive in relation to neurophysiological control of balance?

Answer 10

-visual
-vestibular - inner ear
-somatosensory - ligament, joint receptors, muscle spindles

Question 11

what are the visual inputs?

Answer 11

-reference to the external environment
-if we move we can tell how much we have moved
-we can see how high up we are
-not absolutely necessary for balance & postural control

Question 12

what do the semicircular canals provide input about?

Answer 12

-angular acceleration of the head
-controls the vestibular ocular reflex (VOR)

Question 13

What inputs do the utricle and saccule provide to the brain?

Answer 13

the utricle and saccule detect linear position and acceleration - esp slow movements

Question 14

what is the vestibular ocular reflex?

Answer 14

-The Vestibuloocular reflex (VOR) very well contributes to the maintenance of clear vision.
eg When we move our head to the sides, to maintain a clear vision the eyeballs don’t move along with the head but moves towards the opposite side. These movements of the eyeballs help to fix the gaze on the object and thus we see it clearly[1].

Question 15

compare exocentric vs egocentric mvt

Answer 15

-egocentric mvt - -object motion
-egocentric mvt - self motion

Question 16

what information do the somatosensory inputs provide to the CNS?

Answer 16

-info about the body’s position and motion with reference to supporting surfaces
-info about the relationship of body segments to one another

Question 17

what are the different proprioceptors in the MSK system?

Answer 17

-muscle spindles
-golgi tendon organ
- joint receptors
-cutaneous mechanoreceptors

Question 18

what are Golgi tendon organs?

Answer 18

sensory mechanoreceptors located within tendons

Question 19

what are examples of individual factors that influence balance?

Answer 19

-proprioception
-agility
-strength
-vision
-sensation
-age
-body size

Question 20

what are reactive (compensatory) postural control strategies?

Answer 20

refers to the body’s ability to react to unexpected perturbations or disturbances to maintain balance and stability
- eg being pushed

Question 21

what is anticipatory (predictive) postural control stategies?

Answer 21

Anticipatory postural control involves the proactive adjustment of posture and muscle activity in anticipation of an expected perturbation or movement.
-eg how you walk on ice or snow

Question 22

what is the ankle strategy in relation to postural control strategies?

Answer 22

-involves controlled movements primarily at the ankle joint to counteract perturbations and maintain balance.
-It is typically employed when the body’s center of mass is shifted or destabilized within the base of support, such as a slight lean forward or backward.

Question 23

what is the hip strategy?

Answer 23

Definition: The hip strategy involves controlled movements primarily at the hip joint to counteract perturbations and maintain balance.
It is typically employed when the magnitude or velocity of the perturbation exceeds the corrective capabilities of the ankle strategy alone,

Question 24

what are equilibrium reactions as a type of postural control strategy?

Answer 24

-using arms and trunk to realign the centre of mass

Question 25

what is a change-in-support reaction in relation to postural control strategies?

Answer 25

-BOS moves so COM intersects -ie there is a new base of support

Question 26

Describe 5 conditions are likely to present the physiotherapist with balance problems?

Answer 26

-vertigo - vestibular problem -Parkinson's - not somatosensory, movements are too slow / small stroke - sensory loss and impaired motor output -ankle fracture/ injury - somatosensory and muscle weakness -concussion - vestibular problem

Question 27

what 3 components should be included in a clinical balance assessment ?

Answer 27

-static -dynamic - anticipatory (task involving movement), reactive (giving them a little nudge or lean and release)

Question 28

what are examples of testing static balance?

Answer 28

-observation of postural sway -timed test - single leg stance, tandem stance, eyes open and closed -clinical test of the sensory integration of balance

Question 29

what are examples of testing dynamic balance?

Answer 29

-observation of reaching out of base of support -functional tests - give a set of tasks to do - see how well they can do them -Y balance test

Question 30

what is the clinical test of the sensory integration of balance?

Answer 30

- timed test that measures the influence of the visual, vestibular & somatosensory on standing balance

Question 31

describe the single leg stance test

Answer 31

-measure of postural stability -test performed with eyes open and closed -30 secs hold -best of 3 -static test (not involving active mvt)

Question 32

describe the 'Y balance test'

Answer 32

-test of dynamic anticipatory single leg balance -moving but in a SL stance -used in sports for screening injuries risk -non stance leg reaches 3 directions -tests somatosensory component

Question 33

what 3 directions does the non stance leg reach in the Y balance test?

Answer 33

- anterior -posteromedial -posterolateral

Question 34

what is the functional reach test?

Answer 34

a test for assessing dynamic balance

Question 35

describe the timed up and go test

Answer 35

- used for clinical assessment of balance and mobility in older people with neurological conditions -there is cut off points to predict falls

Question 36

what is the berg balance scale?

Answer 36

-determines a patient's ability (or inability) to safely balance during a series of predetermined tasks. -14 tasks -each task graded on 5 point scale

Question 37

what is the tinoetti balance test?

Answer 37

-assesses a person's perception of balance and stability during activities of daily living and their fear of falling.It is a very good indicator of the fall risk of an individual

Question 38

what is the BESTest ?

Answer 38

quantitative assessment tool that aims to identify the disordered systems underlying the postural control responsible for poor functional balance

Question 39

what kind of populations can the BESTest be used in?

Answer 39

-Neurological conditions eg Parkinson's, Stroke, Cerebellar Ataxia, Neuropathies, Head injury, Multiple Sclerosis, Cerebral palsy -Vestibular disorders, -Cognitive Impairments -Elderly.