A wheel at the origin of the center of mass motion in human walking

Justin Carpentier (1, 2) , Mehdi Benallegue (3) , Jean-Paul Laumond (1, 2)

1 LAAS-GEPETTO - Équipe Mouvement des Systèmes Anthropomorphes
2 CNRS - Centre National de la Recherche Scientifique
3 AIST - National Institute of Advanced Industrial Science and Technology

The center of mass (CoM) is a key descriptor in the understanding and the analysis of bipedal locomotion. Some approaches are based on the premise that humans minimize the CoM vertical displacement. Other approaches express walking dynamics though the inverted pendulum model. Such approaches are contradictory in that they lead to two conflicting patterns to express the CoM motion: straight line segments for the first approaches and arcs of a circle for the second ones. In this paper we show that CoM motion is a trade-off between both patterns. Specifically CoM follows a " curtate cycloid " , which is the curve described by a point rigidly attached to a wheel rolling on a flat surface. We demonstrate that all the three parameters defining a curtate cycloid only depend on the height of the subjects.

Mots clés: human locomotion; analytical model; centre of mass; locomotion signature

Domaines: Biomécanique [physics.med-ph]

Justin Carpentier, Mehdi Benallegue, Jean-Paul Laumond. A wheel at the origin of the center of mass motion in human walking. 2016. ⟨hal-01377361v1⟩