Background:Investigationsofrunninggaitamongbarefootandpopulationshaverevealedapersityoffootstrikebehaviors,withsomepreferentiallyemployingarearfootstrike(RFS)asthefoottouchesdownwhileothersemployamidfootstrike(MFS)orforefootstrike(FFS).Here,wereportfootstrikebehaviorandjointanglesamongtraditionalHadzahunter-gathererslivinginNorthernTanzania.Methods:Hadzaadults(n=26)andjuveniles(n=14)ranatarangeofspeeds(adults:mean3.4±0.7m/s,juveniles:mean3.2±0.5m/s)overanoutdoortrackwaywhilebeingrecordedviahigh-speeddigitalvideo.Footstriketype(RFS.MFS.orFFS)andhindlimbsegmentanglesatfootstrikewererecorded.Results:HadzamenpreferentiallyemployedMFS(86.7%ofmen),whileHadzawomenandjuvenilespreferentiallyemployedRFS(90.9%and85.7%ofwomenandjuveniles,respectively).NoFFSwasrecorded.Speed,thepresenceoffootwear(sandalsvs.barefoot),andtrialdurationhadnoeffectonfootstriketype.Conclusion:UnlikeotherhabituallybarefootpopulationswhichpreferFFSwhilerunning.HadzamenpreferredMFS.andHadzawomenandjuvenilespreferredRFS.SexandagedifferencesinfootstrikebehavioramongHadzaadultsmayreflectdifferencesinrunningexperience,withmenlearningtopreferMFSastheyaccumulatemorerunningexperience.
