2018 Volume 7 Pages 55-62
Gait characteristics vary among people and correspond to individual differences of external and internal traits. Recent studies on autism spectrum disorders (ASD) reported that gait characteristics are associated with a walker's autistic trait. Previous studies measured gait characteristics with walking alone and did not investigate gait characteristics in interactive situations. The goal of this study was to examine the correlation between ASD traits and gait characteristics in typically developed (TD) young adults. The subjects completed a Subthreshold Autism Trait Questionnaire (SATQ) for quantitative measurement of autistic traits. After completing the questionnaire, the subjects participated in walking experiments in pairs using an inertial measurement unit (IMU)-type three-dimensional motion capture system. Two participants walked toward each other and had to avoid collision with their counterparts. The norm in the X- and Y-axis directions of acceleration, and the norm in the X-, Y-, and Z-axis directions of the angular velocity of four body parts (waist, left/right foot, and head) were calculated. In this study, the standard deviation of each norm and the average pitch were used as evaluation indices of the magnitude of sway of the body. Each parameter was calculated in two areas: the Walking Area (from the 3rd to 6th steps) and the Passing Area (from the 7th to 10th steps). Multiple regression analysis was performed to determine the factors that explain the SATQ scores. All explanatory variables were standardized, and a multiple linear regression analysis was performed. The results revealed that when the distance between the two subjects at the time of passing each other was 20 cm, there was a strong correlation between the SATQ score and the standard deviation of the norm of the angular velocity of the waist from the 7th to 10th steps. This finding suggests that compared with TD individuals, individuals with severe ASD traits significantly increase the standard deviation of the norm of the angular velocity of the waist in order to avoid contact with their counterparts.