Michael AB, Scott WD and Van Emmerik REA
In this commentary we discuss how complex and nonlinear analysis methods, multiscale entropy (MSE) and detrended fluctuation analysis (DFA) can provide insights into postural changes in people with multiple sclerosis (MS). Here we highlight key methodological considerations for both MSE and DFA, specifically discuss how MS and aging impact the complexity and adaptability of postural control. As MSE and DFA are both sensitive to technical considerations, we directly address how changes in signal processing and equation parameterization impact outcomes and how these may in turn influence the interpretation of results. Furthermore, we identify how MSE and DFA identify different features of disease progression and how the associated breakdowns in physiological function manifest as postural fluctuation changes within and between different time scales. Finally, we propose a framework that combines these techniques to identify the adaptive and maladaptive changes that accompany MS progression.