Reality of Dynamic Chaos in Biomechanics

Abstract

in the late 20th century, Nobel laureate I. R. Prigogine published his final monograph, the result of two decades of work, in which he argued that dynamical systems theory and determinism cannot be applied to the study of biological systems. At the same time, Prigogine, as well as M. GellMann and R. Penrose, accepted the existence of deterministic Lorenz chaos as a mechanism underlying biological processes. We show that this assumption is incorrect for the organization of human movement. We examined the principal criteria of Lorenz chaos and demonstrated that they are not satisfied in postural movements, i.e., involuntary human movements. At the same time, our results support N. A. Bernstein’s principle of “repetition without repetition” in biomechanics. Bernstein first raised the problem of movement uniqueness in 1947, but this line of research received little attention for more than five decades.