Heather Hodnett
Dr. Michael Pavol,
Department of Nutrition and Exercise Sciences
Oregon State University
Howard Hughes Medical Institute
Older Adult Falls are
an Important Concern
 Each year, about 1/3 of adults over age 65 fall
 20-30% of older adults who fall suffer moderate
to severe injuries, and 2% of falls result in
broken hips
 1 in 5 older adults who break a hip die within 1 yr
 In 2000, the annual medical cost of falls was $19
billion, and it is expected to increase to $54
billion by 2020
Gait Matters
 Most injurious falls occur while walking
 Older adults are more likely to fall if they:
 Walk slower
 Take smaller steps
 Walk with narrower strides
 Have weaker hip abductors
Fall Direction Matters
 Falling sideways increases risk of fracture
6-fold (with direct hip impact, the risk
increases 20- to 50-fold)
Sideways
 Unclear if other aspects
of gait affect fall direction
Forward
Sideways
 Propensity to fall sideways
has been related to a
narrow stride width
Backward
Research Question
Do certain aspects of older
adults’ gait patterns play a role in
the directions they are most likely
to fall?
If so, what are those aspects?
Hypothesis
Sideways fallers will show lesser
mediolateral stability during gait
and have weaker hip abductors
than forward/backward fallers and
non-fallers.
Purpose
To determine whether and how
the gait patterns and hip
abductor strengths of older adults
differ according to the direction of
falls suffered within the past year
The Subjects
 Healthy adults over age 65
 Walk unassisted
 No conditions that alter balance or gait
 Competent and in a sound mental state
 Fit into one of three groups:
 Non-fallers (N=17)
 Forward/backward fallers (N=9)
 Side fallers (N=3)
Data Collection
 Motion capture system
 Body segment movements
 9 cameras
 41 markers
 60 Hz
 Force plates
 Ground reaction forces
 600 Hz
Walking Trials
 ~ 13-foot path
 Even, level surface
 Preferred walking
speed
 One step per force
plate
Example Image
Data Considerations
 Joint angles, rotations, & moments
 Trunk sway
 Center of mass (COM)
distance from the outside
of the foot
 Hip abductor strength
 Compare groups using ANOVA
Minimum COM Medial Distance
from Outside of Foot
120
100
Distance
(mm)
*
*
80
60
40
20
0
Non-fallers
Forward/Backward
Fallers
Experimental Group
Side Fallers
*p < .05
Hip Abduction Strength
Force Generated (N)
300
250
200
150
100
50
0
Non-fallers
Forward/Backward
fallers
Experimental Group
Side fallers
Discussion
 Expected lesser mediolateral stability in
side fallers
 Forward/backward fallers less stable
 May be related to narrow stride width
 Side fallers not different than non-fallers
 May have adjusted gait for safety
 Only 3 side fallers tested so far
 Expected lesser abduction strength in side
fallers
 No difference between groups
Next Steps
 Finish current study
 Further research to determine differences
between sideways, forward/backward, and
non-fallers
 Fall risk classification based on gait
 Possible interventions for decreasing
sideways fall risk in older adults
Conclusions
 No conclusive results yet
 Data suggest:
 Forward/backward fallers exhibit lesser
mediolateral stability in gait
 Hip abduction strength is not related to fall
direction or fall incidence
Acknowledgements
 Dr. Michael Pavol
 Dr. Kevin Ahern
 HHMI Program
 Cripps Scholarship Fund
 LIFE Scholars Program
 Center for Healthy Aging Research