Why* measure walking?
Dr. David Rowe
Physical Activity for Health Research Group
University of Strathclyde
*How?
*Where?
*When?
*Who? *What?
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The original plan …
recap on “wellbeing” why measure WfW?
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BREAKER
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The new plan:
recap on “wellbeing”
why measure walking? (who, what, when, where, how?)
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BREAKER
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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?
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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?
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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?
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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
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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?
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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)
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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
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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