According to the Japan Sport Council’s injury database, there were 29 cases of injury due to unanchored soccer goal posts tipping over at elementary, junior high, and high schools in 2014. According to a report from NPO Anchored For Safety, 42 deaths and 59 injuries occurred in schools and parks from 1979 to 2017 in America.
We conducted three experiments to 1) evaluate the risk of soccer goal posts tipping over, 2) measure the force required to tip over a soccer goal post, and 3) measure the force on soccer goal posts when children hang on the crossbar and sway back and forth. In the first experiment, we measured the force of impact in the event of a soccer goal post tipping over to the ground. In the second experiment, we measured the pull force required to tip a soccer goal post over to the ground. In the third experiment, we developed a chin bar-type apparatus that included two biaxial force sensors and then measured the force applied to the developed apparatus with a child’s swaying.
In the first experiment, we used an aluminum soccer goal post and an iron soccer goal post. The maximum force of impact was 18,980 n for the aluminum post, and 29,283 n for the iron post; these forces are strong enough to result in skull fracture. In the second experiment, the minimum pull force was 242.2 n for the aluminum post. In the third experiment, 10 junior high school students participated and the results showed that the maximum force applied to the bar was 405.4 n.
The results of the three experiments showed that a child can easily tip over an unanchored soccer goal post and that there is a particularly high risk of serious injury.