Postural Control and Balance

what is balance?

a multidimensional concept, referring to the ability of a person not to fall

what is postural control?

controlling the body’s position in space for postural orientation and stability, the ability to maintain equilibrium and orientation in a gravitational environment

what are the postural control strategies typically used?

predictive responses (anticipatory), reactive response (compensatory) or a combo of both, fixed support, change in support

what are the different fixed support strategies?

Fixed support strategies include ankle strategy, hip strategy, weight shift, and suspension, which stabilize the body without changing the base of support.

what is meant by the feedback and feedforward processes for postural control?

feedforward involves anticipated responses for postural instability, feedback involved responses for unanticipated postural instability

what are the three systems contributing to postural control?

somatosensory, vestibular, and visual systems

which system is the fastest and most sensitive to balance disturbance, making it favored under stable surface conditions?

the somatosensory system

which system is fast but less sensitive to balance disturbance, favored under stable surface conditions?

the vestibular system

which system is the slowest system but is sensitive to balance disturbance, favored under stable visual conditions and strong vertical cues?

visual system

what is the reweighting theory?

contributions of each of the sensory systems changes depending on environmental conditions and perturbations applied and demands of the task, theorized that postural control system is able to ‘reweight’ sensory inputs to optimize stability

what is the CTSIB?

the clinical test of sensory interaction in balance, assesses postural control under various sensory conditions

what are the test conditions of the modified CTSIB?

• eyes open, firm surface

• eyes closed, firm surface

• eyes open, foam surface

• eyes closed, foam surface

all conditions performed with feet together and arms crossed over chest

what is the SOT?

sensory organization test, test that progressively isolated each sensory system to objectively quantify an individuals use of each sensory system for postural control

what are the six test conditions of the SOT?

1. eyes open, fixed surface

2. eyes closed, fixed surface

3. sway referenced vision, fixed surface

4. eyes open, sway referenced surface

5. eyes closed, sway referenced surface

6. sway referenced vision, sway referenced surface

postural orientation

ability to maintaain appropriate relationship between body segments, and between body and environment during performance of a task

postural stability

ability to control our COM in the relationship to our base of support

what is static postural control?

refers to the ability to maintain a stable position of the body when stationary (quite sitting or standing), ensuring that the center of mass (COM) remains within the limits of the base of support.

what is dynamic postural control?

dynamic balance or controlled mobility, stabilize the body when support surface is moving of when body is moving on stable surface

describe the characteristics of ankle strategy

the first muscle activation pattern used to control upright stability, distal to proximal muscle activation, body sways at ankles and most commonly used for small perturbations on firm surface, movement is well within the limits of stability

describe the characteristics of hip strategy

used to restore equilibrium in response to larger, faster perturbations, compliant support surface of support surface smaller than feet, the proximal muscles are activated first and as movements approach the limits of stability

what strategy is often used to recover mediolateral stability

weight-shift strategy, which HIPS are a KEY control point of, proximal to distal muscle activation

describe the suspension strategy

a strategy that involves lowering the center of mass by flexing the knees and hips, often used to absorb perturbations and maintain stability. often see this strategy in pediatric populations

what score on the sharpened romberg test indicated two to threefold increased risk of fall?

scores less than or equal to 19 seconds

scores below what on the single leg stance test is associated with increased fall risk in older adults?

scores less than 20 seconds

which tests are used to assess anticipatory and reactive control deficits?

• functional reach test

• multidirectional functional reach test

• modified functional reach test

• external perturbations tests

which tests are used to assess dynamic balance and functionality?

• 5 STS

• Four square step test

• TUG

• 10 m walk test

• BERG balance scale

• Tinetti Test

• Mini-BEST

what is the average gait speed in m/s for men and women in their 60s?

men 1.33, women 1.24

what is slower gait speed an indicator of?

single best predictor of functional decline and disability across several populations

what is a cutoff test score for the TUG and the TUG cognitive?

13.5 seconds, 15 seconds

what score on the TUG indicated a high risk for falls?

greater than 20 seconds

what is the cutoff score of the TUG for community dwelling adults?

13.5 seconds

what score on the BERG balance scale increases the likelihood of multiple falls?

less than or equal to 44 (total score possible is 56)

which scores on the berg indicate a medium fall risk?

40-47

what score on the BBS indicates an 100% change of a fall within 6 months?

less than or equal to 36

what strategies can be used for static balance training?

• change BOS

• change support surface

• shoes vs barefoot

• incorporate changes in arm position

• change visual input

what strategies can be used for dynamic balance training?

• change speed of movement

• incorporate head, trunk, limb movements

• change direction of movement