Comments on "An Optimality Principle Governing Human Walking

The paper in question [G. Arechavaleta, J. P. Laumond, H. Hicheur, and A. Berthoz, “An optimality principle governing human walking,” IEEE Trans. Robot., vol. 24, no. 1, pp. 5-14, Feb. 2008] suggested that human-walking paths minimize variation in curvature and hence can be approximated by the solution to an optimal control problem. This conclusion was reached by analysis of experimental data based on the maximum principle. We correct two errors in this analysis and consider their consequences.