OSAKA -- The Osaka Municipal Board of Education decided Feb. 9 to prohibit children from forming human pyramids and towers at school sporting events from next academic year after a series of accidents.

The ban will apply to students at public elementary, junior high and senior high schools in the city of Osaka. Other municipalities including the Chiba Prefecture city of Matsudo have been considering similar bans, but the city of Osaka is apparently the first to implement one, according to the Japan Sports Agency.

Recently, schools have tended to compete for height in gymnastic formation performances, yet experts have pointed out the dangers of this trend. The Osaka Municipal Education Board established a rule in September last year setting the height limit for human pyramids -- where students kneel on top of each other -- at five levels and the level of human towers -- where students make a circle and stand on the shoulders of those below them -- at three.

So far, 170 cases of pyramid- and tower-related accidents have been reported at public primary and junior high schools this school year, according to the city education board. Of those, 53 cases involved broken bones. The figure for the current school year did not show improvement from the 2014 school year (with 45 cases of broken bones), or from the previous academic year (with 50 cases). Seven cases of broken bones during the current academic year occurred after the height rule was introduced.

Osaka Municipal Education Board Chairman Fujio Omori commented, "While there are students who feel a sense of unity (from working together on gymnastic formations with their peers) and while parents may be moved by their children working hard, there are others who do not feel the same way but cannot voice their opinions. I'm not sure which is the majority, but in light of the fact that there are many accidents, this is not something that should be decided by a majority."

During the Feb. 9 education board meeting, members pointed out that bone fractures have been reported in accidents involving other styles of gymnastic formation besides human pyramids and human towers. The education board is set to examine if regulations are also required for such formation styles.

At the same time, some educators expressed confusion about the gymnastic formation ban. A principal at a public junior high school emphasized that gymnastic formation performances are effective in building unity among students, adding, "The education board has just set limits to the levels of human pyramids and towers. They could have waited a little longer to see how things would go."