Cognitive challenges to mobility training

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Margaret Mak PT, PhDDepartment of Rehabilitation SciencesThe Hong Kong Polytechnic University

Dynamic Control of Gait (1)

X Walking difficulty is one of the cardinal signs that persist despite optimal medication.

X Higher risk of immobility and FALLS (Ashburn et al., 2001a, Post et al., 2007)

X 45-50% of falls occurred in walking (Ashburn et al., 2008)

Slower velocity,longer double support

Ç cadence,not stride length in fast walking

Èpush-off , foot clearance, & arm swing

(Hausdorff et al., 1998, Morris et al., 2001, Sofuwa et al. 2005, Behrman et al., 1998)

Dynamic Control of Gait (2)

X Gait is more affected with Ç task complexity or cognitive demand: È gait speed , stride length & stride to stride variability (Plotnik et al., 2011a,b)

Effect of motor dual task on gait in PD patients - ↓ Gait speed and/or stride length

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Study Task

Bond & Morris (2000) Tray with glasses

Canning (2005) Tray with glasses

Galletly and Brauer (2005) Button press

Rochester et al. (2008) Tray with 2 cups of water

Chawla et al. (2014) Coin transfer

Effect of cognitive dual task on gait in PD patients - ↓ Gait speed and stride length

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Study Task

Rochester et al. (2004) Memory task

Brown et al. (2009) Serial subtraction by 3

Hackney and Earhart (2009) Serial subtraction by 3

Plotnik et al. (2011) Serial subtraction by 3 & 7

Wild et al. (2013) Phoneme counting, Serial subtraction by 3

Stegemöller et al. (2014) Serial subtraction by 3

TreatmentXAvoid dual task

XTrain dual-walking task

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Review paper. Valerie et al. Parkinson Dis 2012

Community ambulation – walking with attention shift cannot be avoided

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Training approaches

X Improve automaticity – balance, gait ability

X Improve cognitive functions - set-shifting ability…

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Available literature in dual-task gait training

X Dual-task gait training with priority given to walking - ↑ gait velocity and stride length in both single- and dual-task conditions (Canning 2005), retention for 30 min (Fok et al. 2010)

X Dual-task gait training with equal attention to both tasks -↑ gait velocity and stride length in dual-task walking, with retention for 30 min (Fok et al. 2010)

X Multi-task training with instruction of divided attention, ↑ gait velocity with retention for 3 weeks (Canning 2008)

X Limitations: X Retention period is short

X Most of the tasks are not functional, Generalization??

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Treatment approaches:

XWho can be trainedXWhat task can be addedXSafeXEffective

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9Improve automaticity – balance, gait ability, then add secondary task

Who can be trained?

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Safety Benefit

Who can be trained?

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Study – dual motor task UPDRS HY Task

Bond & Morris (2000) 13^ - Tray with glasses

Canning (2005) III-20 2.1 Tray with glasses

Galletly and Brauer (2005) 14 Button press

Rochester et al. (2008) 33 - Tray with 2 cups of water

Chawla et al. (2014) - 2.2 Coin transfer

^Webster scale

Who can be trained?

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Study – dual cognitive task UPDRS HY Task

Rochester et al. (2004) - 2.7 Memory task

Brown et al. (2009) 28 2.3 Serial subtraction by 3

Hackney and Earhart (2009) 28 - Serial subtraction by 3

Plotnik et al. (2011) 35 2.1 Serial subtraction by 3 & 7

Wild et al. (2013) III-16 1.9 Phoneme counting, Serial subtraction by 3

Stegemöller et al. (2014) 37 2.1 Serial subtraction by 3

Who can be benefited from training?

X PD with mild disability level – less balance and gait problems, less cognitive impairment, better motor learning ability

X Non-fallers, single fallersX Train balance abilities firstX Add cognitive challenge to walkingX Those with moderate level of severity and frequent

fallers – safety, avoid dual tasks, specific strategies such as cues, cognitive movement strategies, to focus on the motor tasks.

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What task can be added?

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Study UPDRS HY Task

Bond & Morris (2000) 13^ - Tray with glasses

Canning (2005) III-20 2.1 Tray with glasses

Galletly and Brauer (2005) 14 Button press

Rochester et al. (2008) 33 - Tray with 2 cups of water

Chawla et al. (2014) - 2.2 Coin transfer

^Webster scale

What tasks can be added?

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Study UPDRS HY Task

Rochester et al. (2004) - 2.7 Memory task

Brown et al. (2009) 28 2.3 Serial subtraction by 3

Hackney and Earhart (2009) 28 - Serial subtraction by 3

Plotnik et al. (2011) 35 2.1 Serial subtraction by 3 & 7

Wild et al. (2013) III-16 1.9 Phoneme counting, Serial subtraction by 3

Stegemöller et al. (2014) 37 2.1 Serial subtraction by 3

Dual-task gait training – tasks usedXCounting backward (Canning 2005, Fok et al. 2010)

XCognitive tasks: counting backwards by twos and threes, memory recall, generating category lists (fruit, sports), simple arithmetic task (Canning 2008)

XMotor tasks: doing up buttons, carrying a plate with a glass on top and transferring coins between pockets or objects between hands (Canning 2008)

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Most of the task are not functionalAll indoors, no community involvement

What task can be added?

X Functional tasks, include outdoors

X Fall characteristicsX ABC scales:

complex community tasks

X Lower marks esp for outdoor activities

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Training protocol – Multi-system balance and mobility training

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• All balance domains, indoor training• Improve automatic control of balance

and gait• 4 weeks

Balance and mobility training

• Outdoor, shopping malls• Spare attention for the added task• 4 weeks

Add complexity

and dual tasks

Home exercises for 6 more months in parks and malls

Subject characteristicsDemographic data EXP (n=41) CON (n=39) p value

Age 59.4±9.0 62.6±8.9 0.109

Gender (male: female) # 25:16 21:18 0.519

PD duration (years) 7.1±4.3 5.6±3.8 0.103Body Mass Index 22.8±3.4 22.7±3.1 0.861

Hohen & Yahr Stage 2.5±0.3 2.4±0.3 0.198

Non-fallers: fallers ratio # 32:9 36:3 0.074

MDS-UPDRS motor score 29.6±10.4 31.3±11.1 0.362

Non-freezers: freezers ratio # 17:24 16:23 0.968

Daily levodopa equivalent dosage (LED mg) 409.3±288.2

320.8±391.0 0.251

Attendance at training (%) 96.3±5.8 94.2±8.0 0.179

Change of LED form Pre to FU12m 10.9±61.9 27.8±83.2 0.352

6m exercise compliance at FU (no. of completer: non-completer) #

28:13(68%)

21:18(54%)

0.185

# chi-square test20

Postural & Flexibility Ex

Functional Training

Indoor Training

Square Stepping Exercise

Balance Dance with

Music

ModifiedWing Chun

SG

SO

PR

APA

LOSBC

POSTURALCONTROL

Forward reaching Lateral reaching

Alternate weight shifting Heel rocking

Balance dance

Leaning and stepping One-leg standing

Axial rotation Tandem walking and turning

Balance dance

• Step forward 上馬

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Modified Wing Chun

• Step backward 退馬

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Modified Wing Chun

• Respond to push – apply backward step

26退馬

Modified Wing Chun

Sideward “Crab” step 蟹步

• Respond to push – apply sideward step

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• Respond to push – apply turn step

Forward and downward push

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Square stepping

3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4 3 1 2 4

3 2 4 5 1 6 3 2 4 5 1 6 3 2 4 5 1 6 3 2 4 5 1 6 3 2 4 5 1 6

7 1 2 8 3 5 6 4 7 1 2 8 3 5 6 4 7 1 2 8 3 5 6 4 7 1 2 8 3 5 6 4 7 1 2 8 3 5 6 4

Basic Intermediate Advance

SG

SOPR

APA

LOSBC

POSTURALCONTROL

Outdoor Training

↑ Complexity of the learnt task

• Practice balance dance and wing chun in outdoor environment:– Uneven ground– Gentle slope

• Increase movement speed, step size, and complexity

• Increase perturbation speed

Add cognitive challenge• Attention shift during walking - change in

direction or motor plan• Add secondary tasks• Fall prone activities• Ensure safety during practice

Uneven groundWing Chun

Balance dance

↑ Movement complexity

Response to perturbation

Obstacle crossing

↑ Movement complexity

Narrow path

Navigating through winded passage

Walking up and downstairs

↑ Movement complexity

Fall-prone activities training

In and out elevator

In and out escalator

Add complexity dual task

Pull and push door

Walking in a crowdWalk and talk

Add dual task

Walk and talk on phone

Bio constraint

Limit of stability

Anti post adjust

Post response

Sen orientation

Gait stability

Effects: Improve balance and dual-task mobility in both short- and long-terms

Injurious Falls Outcome Post FU12m(a) Ratio of non-injurious fallers: injurious fallers EXP (n=41) 0 12:5

CON (n=39) 0 3:9Risk ratio NA 0.392Odds ratio (95% CI) NA 7.2

(1.35-38.33)Likeihood ratio NA 6.075

Pearson χ² NA 5.855

p NA 0.025*

(b) Ratio of injurious falls requiring healthcare services to all falls (%) EXP (out of 31 falls) 0 19%

CON (out of 20 falls) 0 50%

Odds ratio NA

4.2(95% CI) (1.194-14.541)

p NA 0.021*

(c) Landing with forearm and/or hand in all falls (%) EXP 0 48%

CON 0 20%p NA 0.041*

*p < 0.05

Abbreviations: CI, Confidence interval; CON, the control group; EXP, the experimental group; Post, post-training; FU12m, 1-year follow-up

Reduce injurious fall risk at 12 months follow-up

Manuscript under preparation

Improvement in BESTest scores and dual-task gait

Short-term effects on balance and dual-task gait performance

9 Task-specific training: target all 6 balance domains

9 Context-specific training: match the exercise learnt with daily environment

9 Progressive challenges: start with indoor ex. to learn essential balance skills, then practice complex tasks e.g. fall-prone functions and dual-task gait activities outdoors

9 ↑ attentional abilities to the environment

9 Positive feedback from PTs serves as motivational rewards

41(King & Horak, 2009, Nieuwboer et al. 2009, Morris et al. 2010, Smania et al. 2010, Shen & Mak 2012, 2014, Abbruzzese et al. 2016)

Balance Dance

Square Stepping

Wing Chun

Mobility & strength ex.

Flexibility, Mobility & strength ex.

Balance Dance

Balance Dance

Wing Chun

Square Stepping

Long-term effects on balance and dual-task gait performance

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Improvement in balance, gait & functional outcomes beyond treatment completion, which may imply neural neuroplasticity

(Ellis et al. 2011; Shen et al. 2015)

Training

• Goal-directed interventions on all balance domains• Task- and context-specific• Home exercise guidelines and video demo

Rewards

• Short-term gains to encourage further practice Æskill retention & consolidations

• Use of free-of-charge venues for practice

Behaviour

• Higher % of EXP group completed suggested home ex.

• Establish positive exercise behaviour

Long-term effects on fall outcomes• The first study to report a reduction of injurious fallers

among NFs & SFs after multi-system balance training• EXP group:

– Improved balance and fall-prone functional performance – Better abilities in handling fall-prone situations in outdoor

environment– Use UL more in landing possibly due to practice of arm

responses with Wing Chun• Descent movement with outstretched arms may absorb

some impact energy of falls to other parts of the body (Fasano et al. 2012)

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Injurious fall risk

SummaryXMulti-system balance and dual-task mobility

training enhances balance and dual-task walking performance in PD NF & SF

XReduce injurious fallsX Improvement in functions beyond treatment

completion may imply neuroplastic changes XNot clear whether cognitive training can

improve dual-task mobilityXCognitive training + mobility training may

benefit PD with freezing of gait (Peterson et al. 2016)44

X Christin ShenX Irene WongX Chloe ChungX Hong Kong PD

FoundationX Li Ka Shing FoundationX SK Yee Foundation

Neural Control and Balance Laboratory

Margaret.Mak@Polyu.edu.hk