ABSTRACT
This chapter examines the relation between the nonlinear coupling of components and the complexity of the normal force output from the perspective of global and local complexity. All the subjects signed informed consent forms prior to participation, with approval for the experimental protocol from the Pennsylvania State University Institutional Review Board. The 3 force dimensions were defined as the subcomponents, or local variables, while the relative phase between the resultant force vectors and the transducer surface served as the global variable. The percentage of the total time series in the bin with the highest frequency counts was then calculated as an index of the stability of the global parameter. An inverted-U change was found in the stability of the preferred relative phase mode and the function for the percentage of the time series captured by the peak relative phase value bin was similar to that of approximate entropy.
