Human locomotion analysis: Identifying a dynamic mapping between upper and lower limb joints using the Koopman operator

Human locomotion is a complex process that shows some inherent synergies and coordination, also called inter-joint coordination, between the upper and lower limbs. In this paper, we investigate the use of Koopman operator to identify a dynamic mapping between an upper limb and its contra-lateral lower limb in the human locomotion. We perform a human locomotion analysis in the sagittal plane and restrict the study to the forward motion; more specifically, a straight walking task at a constant speed. We use canes as walking aids to provide additional information about the terrain and enforce a frequency locking between the upper and lower body. This mapping will provide a model of the human locomotion.