THE KINEMATICS AND KINETICS OF THE RUNNING PATTERN OF TWO-, FOUR-, AND SIX-YEAR-OLD CHILDREN

VIRGINIA LORRAINE FORTNEY, Purdue University

Abstract

Purpose. The purpose of the study was to investigate selected kinematic and kinetic variables in the running pattern of two-, four-, and six-year-old children. The selected kinematic variables were studied using cinematographic records of one step of the running pattern. The selected kinetic variables were studied using force-plate tracings during the support phase of that step. Procedures. Twenty-eight Caucasian subjects, fifteen male and thirteen female, were in the study. Two sessions were required, each of approximately forty-five minutes in duration, to complete testing on a given subject. A running path consisting of a start point, the force-plate bordered by timing gates, and a finish point were used. The length of the path was 12.33 meters for the two-year-old group, 18.53 meters for the four-year-old group, and 24.66 meters for the six-year-old group. In both sessions the subject ran two or more warm-up trials. In the first session practice trials simulating testing conditions were timed. In the second session, after the warm-up trials, three timed trials were simultaneously recorded on film and force-plate tracings. A two-by-three (sex-by-age) factorial analysis of variance was used to determine whether effects of variation between and within age and sex factors for each of the dependent variables of selected kinematic (displacement and velocity) and kinetic (force and impulse) variables were significant. One trial was selected for analysis. The one analyzed was the one during which the child demonstrated the fastest run for which both film and force data were available. A FORTRAN program was used for the analysis of variance. In the case of a significant F ratio, a follow-up program, which tested the equality of means by the Turkey criterion, was used to determine which means were significantly different from each other. Results. The ability of the children to attain fast absolute running speeds was reflected by their performance. The running speeds improved with age. Although height and weight gains influenced the improvement shown in performance, certain biochemical variables also contributed to the development of the running pattern. In a majority of the selected kinematic variables and kinetic variables, there were significant differences between the two-year-old group and the other two groups. In variables for which there were significant differences, the differences tended to be in displacement, velocity, and magnitude of force measures rather than in time of occurrence or duration of time measures. Significant differences between boys and girls appeared in five kinematic variables related to the swing leg.

Degree

Ph.D.

Subject Area

Physical education

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