Purpose:Thisstudyexaminedvariationinfootstriketypes,lowerextremitykinematics,andarchheightandstiffnessamongTarahumaraIndiansfromtheSierraTarahumara.Mexico.Methods:Highspeedvideowasusedtostudythekinematicsof23inpiduals.13whohabituallyweartraditionalminimalrunningsandals(huaraches).and10whohabituallywearmodern,conventionalrunningshoeswithelevated,cushionedheelsandarchsupport.Measurementsoffootshapeandarchstiffnessweretakenontheseinpidualsplusanadditionalsampleof12inpiduals.Results:MinimallyshodTarahumaraexhibitmuchvariationwith40%primarilyusingmidfootstrikes,30%primarilyusingforefootstrikes,and30%primarilyusingrearfootstrikes.Incontrast,75%oftheconventionallyshodTarahumaraprimarilyusedrearfootstrikes,and25%primarilyusedmidfootstrikes.Inpidualswhousedforefootormidfootstrikeslandedwithsignificantlymoreplantarflexedankles,flexedknees,andflexedhipsthanrunnerswhousedrearfootstrikes.FootmeasurementsindicatethatconventionallyshodTarahumaraalsohavesignificantlylessstiffarchesthanthosewearingminimalshoes.Conclusion:Thesedatareinforceearlierstudiesthatthereisvariationamongfootstrikepatternsamongminimallyshodrunners,butalsosupportthehypothesisthatfootstiffnessandimportantaspectsofrunningform,includingfootstrike,differbetweenrunnerswhogrowupusingminimalversusmodem,conventionalfootwear.
