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Gait Analysis

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Gait Analysis Powered By Docstoc
					  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)

 Propensity to fall sideways                Forward

  has been related to a
  narrow stride width

                                  Sideways




                                                        Sideways
 Unclear if other aspects
  of gait affect fall direction              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                 *

            80
Distance
  (mm)




            60


            40


            20


             0

                 Non-fallers       Forward/Backward       Side Fallers
                                        Fallers

                               Experimental Group
                                                                  *p < .05
                            Hip Abduction Strength
                      300


                      250
Force Generated (N)




                      200


                      150


                      100


                      50


                       0
                              Non-fallers      Forward/Backward   Side fallers
                                                     fallers

                                            Experimental Group
              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

				
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posted:1/30/2012
language:English
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