Analysis of the human gait rhythm in Neurodegenerative disease: A multifractal approach using Multifractal detrended cross correlation analysis

In this paper the human gait rhythm of the healthy individuals and the patients suffering from a neurological disorder, Amyotrophic lateral sclerosis (ALS) disease has been studied applying a non-linear technique, Multifractal detrended cross correlation analysis (MF-DXA). The autocorrelation and cross correlation of the stride-interval fluctuations between the left foot and the right foot were studied. The results obtained reflect the fact that the degree of multifractality (W) and the degree of correlation (gamma) are greater for the Control group compared to the diseased group. It is evident that the gait pattern of an individual becomes less steady and temporarily more disorganized in neural diseases due to the neuronal deterioration. The results obtained from the autocorrelation study for the left and the right foot are almost identical. It was also observed that the study of the autocorrelation is not always enough to distinguish between the Controlled and the diseased group. The study of the cross correlation between the left and the right foot can then help to recognize the diseased group. The present analysis shows that the cross correlation between the stride-interval fluctuations between the left and the right foot was greater for the healthy individuals compared to the patients with neurodegenerative disease. (C) 2019 Published by Elsevier B.V.