Characterizing Swing-Leg Retraction in Human Locomotion

Lauflabor Locomotion Lab, TU Darmstadt,Darmstadt, GermanyE-mail: {sharbafi/seyfarth}@sport.tu-darmstadt.deSwing-legretraction,thebackwardrotationoftheswinglegjustpriortogroundcontact,isobservedinhumanlocomotion.Whileseveraladvantagesofswing-legretraction,likegaitstabilityandperturbationrejection,areshownbycon-ceptual models, there is currently very little experimental data on swing-legretraction in human motion. In this paper, kinematic data for twenty-eightsubjects walking and running at different speeds are analyzed. Swing-leg re-traction was shown to exist in walking and running at every non-zero speed.Additionally,swing-legretractionspeedandaccelerationlinearlyincreasewithgaitspeed.Atcomparablegaitspeeds,swing-legretractionspeedishigherforrunningthanforwalking.Keywords:Swing-legretraction;walking;running.