3

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

6-12 Teens 20s 30s 40s 50s 60s 70s >80

mete

rs/s

eco

nd

Walking Speed by Gender & Age

Female

Male

Self selected walking speed categorized by gender & age: 6-12 & teens (Waters, Lunsford et al. 1988); 20s-50s (Bohannon 1997); & 60’s-80’s (Bohannon 2008)

Vital Sign

Vital sign is: Walking speed is:

General indicator that can predict future events & reflect various underlying physiological processes (Studenski 2003)

Vital Sign

Crossing the Street

2 traffic lanes (8 m)

Critical speed: 1.14 m/sec

4 traffic lanes (16 m)

Critical speed: 1.33 m/sec

0 mph 0.4 mph 0.9 mph 1.3 mph 1.8 mph 2.2 mph 2.7 mph 3.1 mph10 meter walk 50 sec 25 sec 16.7 sec 12.5 sec 10 sec 8.3 sec 7.1 sec10 foot walk time 15.2 sec 7.6 sec 5 sec 3.8 sec 3 sec 2.5 sec 2.2 sec

10 meter walk 50 sec 25 sec 16.7 sec 12.5 sec 10 sec 8.3 sec 7.1 sec

10 foot walk time 15.2 sec 7.6 sec 5 sec 3.8 sec 3 sec 2.5 sec 2.2 sec

Red Flag: < 0.6 m/s

10 meter walk time 50 sec 25 sec 16.7 sec 12.5 sec 10 sec 8.3 sec 7.1 sec10 foot walk time 15.2 sec 7.6 sec 5 sec 3.8 sec 3 sec 2.5 sec 2.2 sec

Red Flag: < 0.6 m/s

.15 m/s

10 meter walk time 50 sec 25 sec 16.7 sec 12.5 sec 10 sec 8.3 sec 7.1 sec10 foot walk time 15.2 sec 7.6 sec 5 sec 3.8 sec 3 sec 2.5 sec 2.2 sec

Yellow Flag: 0.6 – 1.0 m/s

10 meter walk 50 sec 25 sec 16.7 sec 12.5 sec 10 sec 8.3 sec 7.1 sec10 foot walk time 15.2 sec 7.6 sec 5 sec 3.8 sec 3 sec 2.5 sec 2.2 sec

Green Flag: > 1.0 m/s

(Abellan van Kan 2009)

N= 492 elders (Studenski ,2003)

Walking speed

METS Functionm/sec mph

.67 1.5 < 2 self care

.89 2.0 2.5 household activities

1.11 2.5 3.0 carry groceries, light yard work

1.33 3.0 3.5 climb several flights of stairs

Days to Death

Perc

ent A

live

.4-.6 m/s .6-.8 m/s .8-1.0m/s 1.0-1.2m/s 1.2-1.4 m/s >1.4 m/s0-.4 m/s

Days to Death

Perc

ent A

live

90-95%

70-82%

55-60%

Percent alive at 3000

days stratified by

WS

.4-.6 m/s .6-.8 m/s .8-1.0m/s 1.0-1.2m/s 1.2-1.4 m/s >1.4 m/s0-.4 m/s3000 days=

8.5 years

Improved at 1 year 31.6%Transient improvement 41.2%

Never improved 49.3%

Hardy 2007

0.1m/s improvement in WS

in 1 year

Hardy 2007

70%

60%

50%

Improved at 1 yearTransient improvementNever improved

GAINS in Walking speed predicts……9 year mortality

0.1m/s improvement in WS

in 1 year

Walking Speed Predicts…

…1 year health outcomes

Studenski 2003

0

10

20

30

40

50

60

70

80

iADL Global Health HRQ0L

>1.0 m/sec 0.6-1.0 m/sec <0.6 m/sec

Decline from Baseline to 1 year

% P

opu

lation

% patient declines in one year

stratified by WS

Measurement of Walking Speed

Test-retest reliability coefficients reported in the literature range from:

0.929 (Evans 1997) to 0.97 (Stephens 1999)

safe

cost effective

easy

interpreted

Feasibility of Tests Walking Speed

Reliable, inexpensive method (Perera 2006)

12 meter path

Central 10 meters being the timing area

Reliable

Recommended as most feasible

6 meter path

Central 4 meters being the timing area

Time to complete = meters per second

3 seconds 1.3 m/s

4 seconds 1.0 m/s

5 seconds 0.8 m/s

6.7 seconds 0.6 m/s

Quick Gait Speed Test

1.0 m/s

•

•

True change vs. measurement error Change of 0.1 m/s is predictor

Use a change

of 0.1m/s for

patient goals

Initial Examination Reassessment

IS THIS A MEANINGFUL CHANGE?

Mean difference:

WSreassess –WSinitial = 0.23 m/s

WSMDC = 0.10 m/s

Interpretation of Walking Speed (WS)

Walking Speed IS THE Vital Sign for Function

DANGER

WARNING

COMMUNITY Ambulator