Parkinson’s disease (PD) and basal ganglia dysfunction impair movement timing, and this impairment leads to gait instability and falls. Gait disturbances of PD can occur in numerous ways, including festinating (accelerating) gait, slow shuffling gait, or highly variable random stride-timing. The authors’ research group is studying an ambulatory assistive system that is based on the cooperative gait among human beings for locomotion rehabilitation. In this chapter, they introduce gait disturbances of PD, especially festinating gait, and they introduce an Interpersonal synchrony emulation system between a human and a virtual biped robot, which entrains the gait timings of the human and the robot in a cross-feedback manner by presenting auditory stimulation that indicates the timing of the partner’s foot contact with the ground. In a pilot study that evaluated walking with the system, the festinating gaits of the PD patients were improved, and carry-over effects were observed. These results suggested that the interpersonal interaction seems to be effective for the welfare support of locomotive ability.
Top2. Background
Gait rehabilitation is often performed by cooperating the step timing between a caregiver and the patient with the gait disturbance. One characteristic of such a process is to generate appropriate assistance relations in real time (Muto & Miyake, 2004). Our research group focuses on the process of generating the cooperative functions that are used in the interactions of gaits between humans.
Regarding interpersonal interactions, considerable research attention has been devoted to Interpersonal synchrony and to locomotive control (Condon & Sander, 1974; Ivanenko, Poppele, & Lacquaniti, 2007; Matarazzo, Saslow, Wiens, Weitman, & Allen, 1964; Nagaoka, Komori, & Yoshikawa, 2007). However, for their interactions, the interpersonal synchronization of stepping rhythms, which is widely observed in our daily life, remain relatively unexplored, despite being a common phenomenon that has considerable rehabilitation potential. Therefore, from the perspective of mutual entrainment (Kuramoto, 1984; Strogatz, 2003; Winfree, 1980) of gait rhythm (Muto & Miyake, 2004; Zivotofsky & Hausdorff, 2007), our research group has constructed an Interpersonal synchrony emulation system between a patient and a virtual biped robot that generates pacing signals using nonlinear oscillators (Miyake, 2009; Miyake, Miyagawa, & Tamura, 2004; Miyake & Shimizu, 1994; Miyake, Taga, Ohto, Yamaguchi, & Shimizu, 1994). This system entrains the gait timings of the human and the robot in a cross-feedback manner by presenting auditory stimulation that indicates the timing of the partner’s foot contact with the ground. The Interpersonal synchrony emulation system stabilizes the patient’s gait through mutual entrainment.