Effect of walking speed on the gait of king penguins: An accelerometric approach
Résumé
Little isknownaboutnon-humanbipedalgaits.Thisisprobablyduetothefactthatmostlargeanimals
are quadrupedalandthatnon-humanbipedalanimalsaremostlybirds,whoseprimaryformofloco-
motion is flight. Verylittleresearchhasbeenconductedonpenguinpedestrianlocomotionwiththe
focus insteadontheirassociatedhighenergyexpenditure.Inanimals,tri-axialaccelerometersarefre-
quentlyusedtoestimatephysiologicalenergycost,aswellastodefine thebehaviourpatternofaspecies,
or thekinematicsofswimming.Inthisstudy,weshowedhowanaccelerometer-basedtechniquecould
be usedtodeterminethebiomechanicalcharacteristicsofpedestrianlocomotion.Eightkingpenguins,
which representtheonlyfamilyofbirdstohaveanuprightbipedalgait,weretrainedtowalkona
treadmill. Thetrunktri-axialaccelerationswererecordedwhilethebirdwaswalkingatfourdifferent
speeds (1.0,1.2,1.4and1.6km/h),enablingtheamplitudeofdynamicbodyaccelerationalongthethree
axes(amplitudeofDBAx, DBAy and DBAz), stridefrequency,waddlingandleaningamplitude,aswellas
the leaningangletobedefined. Themagnitudeofthemeasuredvariablesshowedasignificant increase
with increasingspeed,apartfromthebackwardsangleoflean,whichdecreasedwithincreasingspeed.
The variabilityofthemeasuredvariablesalsoshowedasignificant increasewithspeedapartfromthe
DBAz amplitude, thewaddlingamplitude,andtheleaningangle,wherenosignificant effectofthe
walkingspeedwasfound.Thispaperisthe first approachtodescribe3Dbiomechanicswithanaccel-
erometeronwildanimals,demonstratingthepotentialofthistechnique.