11/3/2014

1

Assessment and Treatment of Balance for

PD Rehabilitation

Fay B. Horak PhD, PTProfessor of NeurologyPortland VA and OHSU

Balance Disorders LaboratoriesChief Scientific Officer, APDM

Course Objectives

• Understand how specific impairments underlie balance and gait dysfunction in PD

• Review the clinimetrics of the BESTest and MiniBEST to assess balance in PD

• Observe balance assessment in PD

• Discuss how to rehabilitate specific balance impairments in PD

• Learn how to encorporate cognitive challenges in rehabilitation for mobility

11/3/2014

2

Medium Latency

SpinalCord

Perturbation

Response Synergies

Sensory IntegrationSelect,

Sequence & Automate

Adaptation

Step & Reach ResponsesAPAs

Basal Ganglia

Cerebellum

Motor CortexSMA

Parietal

Cortex

Reticular Formation

Locomotion

Long Latency

Jacobs and Horak, 2007

Balance control involves many different neural circuits

– Dysfunction – can the person perform a specified action or activity? (examples: can’t put on coat, can’t perform sit to stand, can’t walk to the mailbox)

– Impairment - defined as any disorder in structure or function resulting from anatomic, physiologic or psychological abnormalities that interferes with normal functional activities (decreased ROM, decreased strength, pain, etc.)

Two levels of AssessmentBalance and Gait

11/3/2014

3

Commonly used tests for determining level of mobili ty-

dysfunction, not Impairment LevelTest Scores indicating risk for falls/norms

Timed up and go Risk for falls: >13.5 seconds

Mini-BESTest Identifies fallers: score of 20 or below

2-minute walk test Normative Data: Mean (SD) for retirement dwelling older adults; 150.4 (23.1) meters

CTSIB Normative Data:65-84yrs 26-28secs condition 4 65-84yrs 13-19secs condition 5 65-84yrs 14-24secs condition 6

Activities-specific Balance Confidence (ABC) Community: > 80Chronic illness: 50-80Home bound: <50

Dizziness Handicap Index (DHI) Min risk for falls: 0-30Moderate risk: 31-60High risk: >60

Berg Balance Scale Risk for falls: <46

Dynamic Gait Index (DGI) Risk for falls: < 19

5 times sit to stand >60 years: 14.5 seconds<60 years: 10 seconds

CLINICAL BALANCE TESTS - WHAT TO CONSIDER

Pros Cons

11/3/2014

4

Horak, Wrisley, Frank. Physical Therapy 2009

Postural Systems

I. BIOMECHANICS

Upright Control

StoopedControl

Parkinson’s Disease

How could biomechanics impact balance control?

11/3/2014

5

PD Subject

Control Subject

0 1 2 30

5

10

CoP CoM

CoP

CoM

Time (s)0 1 2 3

0

5

10Stability Margin (peak CoP - peak CoM)

5 cmF

B

RL

BL

FL FR

BR

Upright Controls

Parkinson’s Disease (PD)

Stooped Controls

STOOPED INITIAL POSTURE REDUCES POSTURAL STABILITY IN RESPO NSE TO

PERTURBATIONS , ESPECIALLY BACKWARDS (LIKE PD SUBJECTS).

I. BIOMECHANICS

� Base of Support� Postural Alignment� Ankle strength and

range� Hip/trunk lateral

strength� Transfer from Floor

11/3/2014

6

II. VERTICALITY & STABILITY LIMITS

� Sitting Vertically� Sitting Lateral Lean� Limits of stability

Could overshoot, undershoot, asymmetrical

Patient examples of LoS and

improvement

III. ANTICIPATORY POSTURAL ADJUSTMENTS

Horak and Macpherson, 1999, Nashner Cordo

11/3/2014

7

Anticipatory postural adjustments prior to voluntary step initiationare smaller in the elderly and even smaller in subjects with PD

Initial step foot

Initial stance foot

HOW COULD APA PROBLEMS AFFECT FUNCTION ?

Figure l

Figure lll

• People with FoG had more APAs before reactive step

• More APA- slower, shorter, less effective step

11/3/2014

8

III. ANTICIPATORY POSTURAL ADJUSTMENTS

� Sit to Stand� Rise to Toes� Stand on One Leg� Alternate Stair Touching� Standing Arm Raise

Horak and Macpherson, 1999; Nashner and Cordo

Lack of APA for Rise to toes

Lack of APA for One Foot standing

11/3/2014

9

IV. AUTOMATIC POSTURAL RESPONSES

Inability to recover from slips and trips are most common reason for falling!

Strategies for postural responses:

• Ankle• Hip• Stepping

COMPENSATORY STEPPING

Control Subject Subject with Parkinson’s

11/3/2014

10

Push and Release Test

Better sensitivity and reliability than Pull Test

Correlates better with ABC, UPDRS, Falls

Inter-rater = .98

N = 99 PD and Control subjects

Jacobs, Nutt and Horak, 2006

Slips and trips most common reason for falling!

IV. AUTOMATIC POSTURAL RESPONSES

� In-place forwards� In-place backwards� Step forward� Step backwards� Step sideways

11/3/2014

11

Feet In Place Push and Release

V. SENSORY ORIENTATION

Sensory Weighting

Firm Surface– 70% Somatosensory– 20% Vestibular– 10% Vision

Unstable Surface– 60% Vestibular– 30% Vision– 10% Somatosensory

11/3/2014

12

V. SENSORY ORIENTATION

� EYES OPEN FIRM

� EYES CLOSED FIRM

� EYES OPEN FOAM

� EYES CLOSED FOAM

� STAND ON INCLINE

VI. Dynamic Stability (Gait)

Stability in Gait

Level Surfaces

Change in Speed

Walk with Head Turns

Walk with Pivot Turns

Step over Obstacle

Timed “Get up &

Go”

Timed “Get up &

Go w/Cognitiv

e Test

11/3/2014

13

TUG with and without Dual Task

IV. STABILITY IN GAIT

� GAIT – LEVEL SURFACES

� CHANGE IN SPEED

� WALK WITH HEAD TURNS

� WALK WITH PIVOT TURNS

� STEP OVER OBSTACLE

� TIMED “GET UP & GO”� TIMED “GET UP & GO” WITH

COGNITIVE TASK

11/3/2014

14

THE BALANCE EVALUATION SYSTEMS TEST TO DIFFERENTIATE BALANCE DEFICITS

Horak, Wrisley, Frank, Physical Therapy 2009

BESTest

Inter-rater reliability across diagnoses Clinical validity of BESTest

Fay B Horak, Diane M Wrisley, James Frank: Physical Therapy 2009

PSYCHOMETRIC PROPERTIES OF BESTEST• ICC range: .79-.95 (in each category)

11/3/2014

15

PSYCHOMETRICS TO SHORTEN THE BESTEST:THE MINI-BESTEST

115 Rehab Patients• Stroke• Hemiparesis• Neuromuscular• Ataxia• MS• Neuropathy• TBI• Other

115 Rehab Patients• Stroke• Hemiparesis• Neuromuscular• Ataxia• MS• Neuropathy• TBI• Other

BESTest by PTs

BESTest by PTs

Dimensionality• Confirmatory

Factor Analysis• Horn’s Parallel

Analysis• Explanatory

Factor Analysis

Dimensionality• Confirmatory

Factor Analysis• Horn’s Parallel

Analysis• Explanatory

Factor Analysis

Rasch Analysis• Eliminate

Redundant Items

• Reduce Categories

• Evaluate Spread of items/subjects

Rasch Analysis• Eliminate

Redundant Items

• Reduce Categories

• Evaluate Spread of items/subjects

Franchignoni et al. Journal of Rehabilitation Medicine 2010.

I. Biomechanical

Constraints

II.Stability Limits

III.Anticipatory-Transitions

1. Base of Support

2. Alignment

3. Ankle Strength

4. Hip Strength

5. Sit on Floor and Stand Up

6a. Lateral Lean- Left

6b. Lateral Lean R

6c. Sitting Verticality L

6d. Sitting Verticality R

7. Forward Reach

8a. Reach L

8b. Reach R

9. Sit to Stand

10. Rise to Toes

11a. Stand on Left Leg

11b. Stand on Right Leg

12. Alternate Stair Touch

13. Standing Arm Raise

IV.Postural Responses

V. Sensory Orientation

VI.Dynamic Gait

14. In-place forward

15. In-place backward

16. Stepping forward

17. Stepping backward

18a. Stepping L

18b. Stepping R

19a. Stance EO

19b. Stance EC

19c. Foam EO

19d. Foam EC

20. Incline EC

21. Gait Natural

22. Change Speed

23. Head Turns

24. Pivot Turns

25. Obstacles

26. (Get Up and Go)

27. Cognitive Get Up and Go

BESTest Scores:Black Items

(3) Normal(2) Mildly affected(1) Moderately affected(0) Marked Impairment

MiniBESTest Scores:Red Items

(2) Normal(1) Impaired(0) Absent or severe

N= 100

11/3/2014

16

MiniBESTest

Franchignoni, Horak, Godi, Nardone, Giordano, J Rehab Med, 42 (4): 323-31, 2010

Padgett P K et al. PHYS THER 2012;92:1197-1207© 2012 American Physical Therapy Association

BRIEF BESTEST

N=20

11/3/2014

17

• Can BESTest measure declining balance with age?

AGE RELATED QUESTIONS

http://www.acpinternist.org/i/observer/nov2005/gait_lg.jpg

http://thepurebar.com/blog/2012/09/27/balance-training/

http://i.dailymail.co.uk/i/pix/2008/07/28/article-1039396-0219657300000578-791_468x605.jpg

http://4.bp.blogspot.com/-bvXj3R373IM/UksBpGVZdRI/AAAAAAAAAUE/gYWYv2EpWLA/s1600/Wiki-tai%2Bchi-Garry%2BKnight.jpg

O’Hoski, Winship, Herridge, Agha, Brooks, Beauchamp, & SibleyPhysical Therapy 2013

BESTEST MINIBEST BRIEF BESTEST

• N=79 (Healthy Adults ages 50-80)

ALL VERSIONS OF BESTEST CAPTURED DECLINING

BALANCE IN NORMAL AGING

Statistical differences between each age group for each test

11/3/2014

18

King, L. A., Priest, K. C., Salarian, A., Pierce, D., & Horak, F. B. Parkinson's disease, 2012

MINIBEST HAS LESS CEILING EFFECTS

THAN BERG BALANCE SCALE

Berg MiniBEST

MiniBEST

Ber

g B

alan

ce S

cale

BETTER SENSITIVITY AND SPECIFICITY THAN BERG BALANCE

Sensitivity: True positive rateSpecificity: True negative rate

Parkinson’s Disease

Stroke Charlotte SL, Tsang et al.,Phys Ther, 2013

MiniBESTest

Mild MildModerate Moderate

Ber

g B

alan

ce

Min

iBE

ST

MiniBEST BERG TUG

11/3/2014

19

Ryan P. Duncan and Gammon M. Earhart Parkinson’s Disease,2012; Mak M, et al 2013

MINIBESTEST PREDICTED FALLS

BETTER THAN GAIT SPEED IN PD

N= 56 people with PD followed for 6 months

MiniBEST had highest ability to identify fallers prospectively

MiniBEST

Minimal detectable change (MDC) for MiniBEST and Berg

Godi M et al. PHYS THER 2013;93:158-167

© 2013 American Physical Therapy Association

• N = 93 with balance deficits

• 3 raters• Before and after 10 PT

sessions

MDC: A statistical estimate of the smallest amount of change that can be detected by a measure that isn't the result of measurement error

Responsiveness: Clinical judgment of improvement

11/3/2014

20

• Biomechanics -dynamic strength and ROM can’t be predicted by static measures

• LOS-Functional reach does not equal COM movement.

• APAs - too small in PD, too large in ataxia (same score-can see difference)

• Gait and TUG- could have slow speed for many different reasons

• Postural Responses - could be too late, too small, too large-you would get the same score

• Sensory Orientation -could be ML/AP instability, could be strategy problem, slow drift versus high velocity sway

BESTEST GUIDES TO THE SYSTEM

BUT NOT IMPAIRMENT WITHIN SYSTEM

• Not objective as we would like

• Could have same problem in activity for different reasons (impairments)

• Ceiling effects: May not be as sensitive as required for mild balance deficits (i.e. concussion)

• Low resolution for small changes

• Function based-not impairment level of information

LIMITATIONS OF CLINICAL RATING SCALES

11/3/2014

21

• Feet in-place• Stepping

DEMONSTRATE PUSH AND RELEASE

Website www.BESTEst.us

For educational video examples of scoring, forms, questions, languages, etc.