9/18a Postural Control (PT Integrative Care)

Question 1

Define postural control

Answer 1

• involves controlling body’s position in space for stability and orientation
• Enables postural orientation and postural stability
• PTs treat balance disorders more than any other condition

Question 2

define postural orientation**

Answer 2

• how you hold your body in space in relation to other body segments and between the environment for a TASK
• Very FIRST thing you look for and treat in a patient**
• How you orient your center of mass distribution over your base of support

Question 3

define postural stability

Answer 3

• Balance
• ability to control COM in relation to the base of support
• there is a difference between maintaining postural stability and controlling it

Question 4

what does it mean to maintain postural stability

Answer 4

to stabilize one position

Question 5

what does it mean to control postural stability

Answer 5

allows COM to move outside of BOS, but you have the ability to bring COM back to the original position

Question 6

BOS

Answer 6

Base of Support

-area enclosed by the contact of your body with the support surface

Question 7

COM - finalize the COM (L2 or S2?)

Answer 7

Center of Mass

• point in space at the center of the total body space (3D space), normally L2?
• lower the COM, the higher the stability
• above knee amputation causes the COM to shift upwards and causes the patient to have a longer lever arm to topple him from his base of support

Question 8

COG

Answer 8

Center of Gravity

• vertical projection of the COM on a 2D plane (usually the floor)
• COG within BOS and COM directly over it = high stability
• COG outside of BOS = low stability

Question 9

Example of shifting COG to change stability

Answer 9

1. most stable - slouched position where COM is directly over the COG
2. stable - sitting up straight challenges balance b/c COM moves to perimeter of BOS
3. less stable - raising hands over the head to increase the height of the COM
4. least stable - move trunk in a backwards lean to move COM outside of BOS perimeter

Question 10

COP

Answer 10

Center of Pressure

• the center of distribution of total forces applied to the support surface
• represents the average location of the ground reaction force vector from a 2D plane
• sum of reaction forces applied at the COG

Question 11

Example of the body utilizing COP

Answer 11

when in quiet stance, the CNS activates your muscles to bring your COM back to where your COP is

Question 12

Static balance

Answer 12

ability to maintain COG within the supporting base while standing or sitting

Question 13

Dynamic balance

Answer 13

maintaining an upright position while COG and BOS are moving and the COG is moving outside of the supporting base (walking)

Question 14

Functional Balance

Answer 14

ability to perform daily movement tasks requiring balance and involves static and dynamic balance

Question 15

describe the relationship between postural orientation and stability

Answer 15

• stability and orientation are planned around the task

- postural orientation affects postural stability – it is altered to regain postural stability

Question 16

Stability Limits**

Answer 16

• the boundaries within which the body can maintain stability without changing/altering the base of support
• previously noted as the area of the base of the feet
• currently, result from the interaction between the position and the velocity of COM
• –as you increase velocity, you go beyond the stability boundaries
• –stability limits are changed with practice

Question 17

what is a good way to challenge a patient with stability limits?

Answer 17

change the:

1. COM position
2. COM velocity

Question 18

Why is understanding motor control of postural equilibrium and stability SO important?

Answer 18

1. provides a base and framework for assessing balance
2. provides scientific basis for treating postural control deficits
3. helps us predict which patients were at risk
4. helps us predict which patients will improve and with what interventions

Question 19

Assessing balance

Answer 19

• proactive/feedforward control (anticipatory)
• reactive/feedback control (compensatory)
• sensory systems
• —visual (visual anchors help with stability)
• —proprioception
• —vestibular
• —tactile (tactile anchors help with stability)

Question 20

how do you test anticipatory/feedforward control in the clinic?

Answer 20

a patient has a task to raise their deltoid, in preparation to do so he/she flexes/controls abs beforehand

Question 21

feedback control: reactive postural strategies

Answer 21

response depends on multiple factors:

1. amount of perturbation
2. properties of support surface
3. speed of perturbation
4. pathology and pain

Question 22

where in the CNS is balance controlled?

Answer 22

cerebellum controls balance, movement, coordination

Question 23

Principles of balance training

Answer 23

• enhancing individual capacity for: Force, Motion, Energy
• Correct postural orientation (alignment)
• Improving TASK performance
• –patients should feel UNSTABLE during treatment
• —-do so by changing the environment, task, cognitive load, and sensory challenges