Development of the Overarm Throw: Movement and Ball Velocity Changes by Seventh Grade

Abstract Children studied longitudinally from kindergarten through second grade were refilmed in seventh grade as they performed 10 trials of the forceful overarm throw. The horizontal ball velocities of the 22 boys and the 17 girls were compared with predictions made when the children were in second grade. The original estimate of an annual rate of change (a “developmental year”) of 5–8 feet/sec/year (1.52–2.44m) remained accurate for the boys; the original estimate for the girls had to be increased to 2–4.5 feet/sec/year (.61–1.37m). While the gap between the sexes increased throughout elementary school, it increased at a slower rate from second to seventh grade than it had during the primary years. By seventh grade, however, the girls were 5 developmental years behind the boys. The data also suggested a difference in the degree to which the sexes maintained their relative positions within their groups: girls appeared more stable than boys across the elementary years. Change was also assessed in the developmental levels exhibited by the children as they threw. The girls' rate of development was 5–6 years behind the boys' rate. Few boys, however, had reached an advanced level in all movement components by seventh grade. Self-reports suggested that the boys had participated in more overarm throwing than had the girls.