Abstract
Today, falling is a major health problem for aging population. It generates a cascade of health complications such as dependence, social isolation, death, depression, etc. This doctoral work aimed to treat falling via an innovative framework: the theory of complex systems. First, we focus on interpersonal synchronization, i.e. the interaction between two complex systems, and we propose a new methodology to analyze this phenomenon. Next, we show that the complexity matching effect could represent a suitable approach for the study of interpersonal interaction. Therefore, in a second step, we propose a walking rehabilitation protocol based on the phenomenon of complexity matching and allowing to restore the complexity of the locomotion system in the elderly. We show that a regular training of 3 weeks in synchronized walking (elderly subject + young guide) can restore the complexity of walking in seniors (up to 2 months post-protocol). In addition, this restoration of complexity results in a reduction in the fear of falling and an improvement in the overall health of seniors.