BERTRAM, J.E.A.*; RUINA, A.; COX, D.E.; KATSANOS, C.S.: Speed, step length and frequency in human walking: evaluating the optimization criteria.

Locomotion is an active process that involves an interaction between physiological and physical features of an organism. The result of this interaction is the overt functional behavior of the system, its capabilities and limitations. But can the physiological and physical influences be discriminated? We use the walking human as a model system to investigate the factors influencing gait pattern, as indicated by the selection of step length and frequency to provide walking speed. We hypothesize that the selection of these variables depends on the minimization of the locomotory cost function under the explicit circumstances involved, i.e. the solution is a constrained optimization. We compare walking behavior of 6 male and 6 female subjects with predictions based on individual locomotion cost. The results verify the basic model, but also demonstrate that other factors influence the outcome as well.