Postural Control and Balance

Question 1

Postural control emerges from the interaction of what systems?

Answer 1

1. Sensory (afferent) input
   - Visual
   - Vestibular
   - Somatosensory
2. CNS Integration
   - Processes affferent input and determines appropriate output
3. Motor (efferent) output
   - Execution of motor responses (muscle synergies, timing, force)

Question 2

Reactive Postural Control
(Postural Control Strategies)

Answer 2

Occurs in response to external perturbations displacing the COM or a moving surface

Feedback mechanism (dependent on sensory feedback from body)

Question 3

Proactive (Anticipatory) Postural Control
(Postural Control Strategy

Answer 3

Occurs in anticipation of internal perturnations (ie catching a weighted ball)

Prior experience allow the postural control system to be pre-tuned or anticipate the upcoming postural adjustments

FeedFORWARD mechanism (based on learning and experience)

Question 4

Ankle Strategy
(Motor Strategy)

Answer 4

COM is shifted forwards or backwards by moving the body as a relatively fixed pendulum with the ankle joint acting as the axis

• fixed support strategy
• mm activiation occurs from DISTAL to PROXIMAL
• commonly used in response to small displacements of the COM which are still wtihin the LOS

Forward sway:
Gastroc -> Hamstring -> paraspinals
Backward sway:
Tib Ant -> Quads -> Abdoms

Question 5

Hip Strategy
(Motor Strategy)

Answer 5

COM is shifted forwards or backwards by flexing or extending the hip. The head and hips move in opposite directions

• fixed support strategy
• mm activation occurs from PROXIMAL to DISTAL
• Commonly used in response to larger and faster displacement of the COM which exceed the LOS (> mvmt = > strategy)
• More commonly used in the elderly

Forward sway:
Abdoms -> Quads - push backwards (stick butt out)
Backward sway:
Paraspinals -> Hamstrings - push from behind = thrust hips forward & lean head back (ex. edge of pool)

Question 6

Stepping Strategy
(Motor Strategy)

Answer 6

Re-establishing a new BOS through movement of a limb to a new contact support surface

• change in support strategy
• rapid steps or hops are taken in the direction of the COM in order to establish a new BOS, placing the COM within the newly established BOS

Question 7

FUNCTIONAL BALANCE GRADES
4 = NORMAL

Answer 7

• Patient is able to maintain steady balance without handhold support (static)
• Patient accepts maximal challenge and can weight shift easily within full range in all directions (dynamic)

Normal -> Good -> Fair -> Poor -> Absent

Question 8

FUNCTIONAL BALANCE GRADES
3 = Good

Answer 8

• Patient able to maintain balance without handhold support, limited postural sway (static)
• Patient accepts moderate challenge, able to maintian balance while bending to pick an object up from the floor (dynamic)

Normal -> Good -> Fair -> Poor -> Absent

Question 9

FUNCTIONAL BALANCE GRADES
2 = Fair

Answer 9

• Patient requires handhold support, occasional minimal assitance (static)
• Patient accepts minimal challenge, able to balance while turning head/trunk (dynamic)

Normal -> Good -> Fair -> Poor -> Absent

Question 10

FUNCTIONAL BALANCE GRADES
1 = Poor

Answer 10

• Patient requires handhold support and moderate to maximal assistance to maintain position (static)
• Patient unable to accept challenge or move without loss of balance

Normal -> Good -> Fair -> Poor -> Absent

Question 11

FUNCTIONAL BALANCE GRADES
0 = Absent

Answer 11

Patient is unable to maintain balance

Normal -> Good -> Fair -> Poor -> Absent

Question 12

The Romberg Test

Answer 12

Helps to determine proprioceptive contributions to balance
- Feet together with arms by their sides, wtih eyes open (EO) for 2-30 sec. If unable to maintain balance test is stopped (no longer a valid measure)
- Repeated with eyes closed (EC)

(+) Pt is able to stand with EO, but is unstable or falls wtih EC

Test is not appropriate for these pops:
- Vestibular dysfunction
- Cerebral
- Cerebellar Ataxia

Sharpened Romberg Test = tandem stance

Question 13

Functional Reach Test

Answer 13

Provides a quick screen for checking balance problems in older adults

• <6 inches is predictive of falls
• Three trials are performed and the average of the last two are recorded (1st is a practice)

Question 14

BERG Balance Scale

Answer 14

Used to assess both static and dynamic balance and determine the risk of falls in adult populations using 14 seperate ities
- item scores are summed; maximum score of 56 (ceiling)
- DEC score = INC risk of falls

General impressions:
- 41-56 = low risk of falls
- 21-40 = medium falls rick (walking with assistance)
- 0-20 = high fall risk (W/C bound)

Question 15

Get Up & Go Test (GUG)

Answer 15

Brief measure of dynamic balance and mobility

Pt is instructed to stand up from the chair and walk 3 meteres at their NORMAL speed, turn around, return, sit down in the arm chair

Graded 1-5
- >/-3 = increased risk of falling

Assistive devices may be used but must be documented - USE the same device they typically use

Question 16

Timed-Up & Go Test (TUG)

Answer 16

Used to assess mobility, balance, walking ability, and fall risk in older adults

Standardized instructions
Pt is allowed 1 practice trial, and is to use the same aid throughout all the trials

• Observe for patient’s postural stability, appropraite use of walking aid, gait, stride length and sway

General intrepretations:
< 10 sec = normal for most adults
>12 seconds = falls risk
11-20 sec = w/in nomral limits for frail elderly or individuals w/ disability
>30 = impaired functional mobility