幼児期における歩行から走運動への発達過程に関する追跡的研究

Abstract

The purpose of this study was to investigate the development of locomotion in infants by continually observing the process of transition from walking to running ability. The subjects were 8 healthy boys and girls aged from 10 to 18 months. Their locomotion with maximal effort was videotaped using two VTR cameras operating at 60 fps. Three-dimensional coordinates of endpoint segments of the body were obtained using the DLT method. Kinematic parameters for analysis of locomotion were mean speed, step length, step frequency, and step width. In the process of transition from walking to running, the mean speed increased from 1.44 m/s to 1.72 m/s, and the step length and step length/body height ratio also increased from 34.4 cm to 41.9 cm, from 42.9% to 51.7%, and from 3.96 Hz to 4.22 Hz, respectively, although the increase was not significant. We found that there was a leap was involved in the process of progression from walking to running; there was a non-support phase on the leap in one step, and a non-support phase in at least two steps during the running motion. The mean speed of the leap was similar to that of the running motion, and the mean step length and step length/body height ratio were similar to those in the running motion. The mean step frequency was lower than for both the walking and running motions. We speculate that in infants the leap is repeated until it stabilizes into a running motion, and we consider such leaping to be part of the development of the transfer movement during progression from walking to running ability.