why* measure walking? *who? *what?ewds.strath.ac.uk/portals/50/ias documents/walking for...

Why* measure walking?

Dr. David Rowe

Physical Activity for Health Research Group

University of Strathclyde

*How?

*Where?

*When?

*Who? *What?

1

The original plan …

recap on “wellbeing” why measure WfW?

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The new plan:

recap on “wellbeing”

why measure walking? (who, what, when, where, how?)

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Outline

What is walking for wellbeing (WfW)?

Why measure WfW?

What instruments measure WfW?

How to choose a WfW measurement instrument?

How to use WfW data?

4

Questions I get asked a lot …

Which pedometer should I buy?

How much money should I spend on a pedometer?

Should I buy a pedometer that tells me calories?

What is the best method for measuring walking?

5

Questions I asked you …

Why do you want to measure walking?

What is the most important thing you want to take from this session?

How do you plan to use the information you learn in this walkshop?

How many steps should we (adults) take per day to maintain and improve health?

6

The Evolutionary Model of Walking:

What is “walking for wellbeing”?

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What is “walking for wellbeing”?

Activity:

Pair up

Stand up

2 x 1-minute telling each other what you think defines “walking” for “wellbeing”

Re-watch the series of photos

Is this “walking for wellbeing”?

If so, why?

If not, why not? 8

Definition(s) of walking

Bipedal locomotion

Ambulatory physical activity

Stepping

A behavior

Characteristics: rhythm, direction, location, movement, intensity, frequency, duration, efficiency, context

Classifications: occupational, commuting, leisure

9

What differentiates walking “for wellbeing”?

Higher intensity?

Bouts vs. intermittent?

Healthy steps “up and about” steps?

Is definition the same for different outcomes? Cardio-metabolic health?

Bone health?

Weight management?

Mortality?

Mental health and spirituality?

10

Why measure walking?

I really am asking YOU!

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Why measure walking?

Understand the determinants of WfW

Answer questions about relationships between walking and wellbeing-related outcomes

Determine if an intervention has an effect on WfW behavior

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Determine prevalence of WfW

Including whether someone is meeting walking recommendations, e.g., 10,000 steps per day(???)

Why measure walking?

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How to measure walking?

Yes, I really am asking YOU again!

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Most Common Methods for Measuring Walking

Self-report (questionnaires and diaries)

Pedometers

Accelerometers

GPS (GIS)

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How to choose?

Practicality

Reliability

Validity

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How to choose - practicality

Cost

Purchase and per-use

Convenience (user and “tester”)

Burden

Compliance

Complexity

Time

“Fail” rate?

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The Accuracy-Practicality trade-off

Accuracy

Pra

ctic

alit

y

Questionnaire

Pedometer

GPS

Accelerometer

Region of “No Use”

Region of “No Chance”

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How to choose - reliability

Reproducibility

Dependability

Consistency

Instrument “performs” consistently, regardless of:

Which make or model

What time/which occasion

Time frame (number of days)

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9403 9227 9073 9186

8186

10504

4000

5000

6000

7000

8000

9000

10000

11000

Yamax AE120 AE120XL WFL Omron Actigraph

Type of M onitor

Steps/day for Various Activity Monitors

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Individual discrepancy act

ivPAL –

NL-

1000 s

teps

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How many days?

# of days RXX (children)

RXX (middle-aged) RXX (older)

2 .69 .64 .90

3 .71 .73 .92

4 .75 .78 .92

5 .77 .82 .93

6 .79 .84 .94

7 .87 .96

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Which days?

8000

8500

9000

9500

10000

10500

SUN MON TUE WED THU FRI SAT

n=23

Adapted from: Tudor-Locke et al (2004) A Preliminary Study of One year of Pedometer Self-Monitoring Annals of Behavioral Medicine, 28, 158-162

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What time of year?

8000

8500

9000

9500

10000

10500

11000

11500

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NO

VDEC

n=23

Adapted from: Tudor-Locke et al (2004) A Preliminary Study of One year of Pedometer Self-Monitoring Annals of Behavioral Medicine, 28, 158-162

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BSc Students (2013)

25

BSc Students (2012)

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BSc Students (2011)

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How consistent are individuals?

0

5000

10000

15000

20000

25000

TH FR SA SU MO TU WE

P1

P2

P3

P4

P5

Selection of data collected from individuals 28

Which days, and how many?

Generally speaking:

Both weekend days

At least 2, preferably all weekdays

Do the same for everyone

Sufficient number of days for reliability of at least RXX = .80

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How to choose - validity

The “heart” of the matter

Does the instrument measure what you want to measure?

Does it enable you to do what you want with the data?

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Validity paradigm

From: Rowe, D., & Mahar, M. (2006). Construct validity. In T. Wood & W. Zhu (Eds.), Measurement theory and practice in kinesiology (pp. 9-26). Champaign, IL: Human Kinetics.

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Does the instrument measure what you want to measure?

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Definitional Stage

Define the construct (“walking for wellbeing”)

What it is

What it is not

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Domains of Walking

Theoretical domain

The domain of the construct

Operational domain

The measurement domain

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Domains of Walking

THEORETICAL OPERATIONAL

QUESTIONNAIRES

PEDOMETERS

ACCELEROMETERS

GPS

FREQUENCY

BUILT ENVIRONMENT

DURATION

INTENSITY

SOCIAL CONTEXT

DISTANCE

ENERGY EXPENDITURE

DAILY DIARY

GIS

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Domains of Walking

THEORETICAL OPERATIONAL

FORCE PLATFORM

TELEMETRIC EMG

IN-SHOE PRESSURE PAD

PEAK 3D SYSTEM

STEP LENGTH

JOINT TORQUE

ANTERIO-POSTERIOR FORCES

DOUBLE SUPPORT TIME

CENTER OF MASS

VERTICAL FORCE

36

Jingle, jangle fallacies

Rockport “walk” test

50 ft “walk” test

YMCA “step” test

SFT “step in place” test

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Measures of Walkability

Scottish Walkability Assessment Tool

Walkability Index

Walkability Checklist

Walking Security Index

Walking Permeability Index

Pedestrian Potential Index

Pedestrian Performance Measure

Pedestrian Environmental Factor

Pedestrian Infrastructure Prioritization System

Pedestrian Sketch Plan Method

Pedestrian Deficiency Index

Pedestrian Level of Service

Pedestrian Level-of-Service

Florida Pedestrian Level of Service

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Dimensions of Walkability

Spatiophysical

38 dimensions, 95 characteristics

Paths; path width

Spatiobehavioral

10 dimensions, 30 characteristics

Safety; automobile-pedestrian crash factor

Spatiopsychosocial

4 dimensions, 30 characteristics

Perception of walking; comfort

Policy

5 dimensions, 24 characteristics

Plans and programs; public/private partnerships

Moudon & Lee (2003) Walking and bicycling: an evaluation of environmental audit instruments Am J Hlth Prom, 18(1), 21-37

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Measurement of WfW

Dimension Q’aire Pedometer Accelerometer GPS/GIS

Steps + +++ +++ (++)

Distance + ++ ++ +++

Speed/cadence + (+) +++ +++

Time + (++) +++ +++

Location + +++

Social ++

Other “context”

++

[+ measures somewhat accurately; ++ measures moderately accurately; +++ measures very accurately] 40

Does it enable you to do what you want with the data?

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Why measure walking?

Detect individual differences

Detect change

Investigate relationships

Report prevalence “meeting recommendations”

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Tudor-Locke (2001) RQES

0

2000

4000

6000

8000

10000

12000

Baseline Post-

intervention

0

20

40

60

80

100

Baseline Post-

intervention

Pedometer (steps/day) Activity Log (kcal/kg/day)

ES = 1.68 ES = -0.03

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How to decide?

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Activity #2

Refer to handout for “Instrument selection” activity

Work in groups

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TIME TO WALK! 46