| Nonlinear Dynamics, Psychology, and Life Sciences, Vol. 19, Iss. 4, Oct, 2015, pp. 395-418 @2015 Society for Chaos Theory in Psychology & Life Sciences Dimension and Complexity in Human Movement and Posture Abstract: There has been considerable effort over the last 25 years to
understand the emergence of complexity in motor output and how this
relates to properties of the individual (e.g., age, disease state, etc.),
environment (e.g., information) and task (e.g., movement, posture, isometric force).
This paper addresses the behavioral dimension of motor complexity in movement
and posture from a degrees of freedom (DF) perspective together with the
change of complexity through aging, disease and fatigue. The dimension of behavior
for a given perceptual-motor output is shown to be relatively low, dependent on the
interaction between the individual, environmental, and task constraints and
varies within a limited adaptive range for a given motor task. The determination of dimension
in movement and posture has taken us beyond the traditional
motor performance scores of behavior but it is not a sufficient characterization
of the adaptive and emergent processes of complexity. Keywords: posture, fractal dimension, entropy, principal components analysis |