Bodychecking
This is the only major international tournament in Women's ice hockey to allow bodychecking. Before the tournament, bodychecking had been allowed in women's ice hockey in Europe. The European teams, knowing that they were less competitive than the North American teams, asked for bodychecking to be included. For some reason, the Europeans failed to realize the fact that while European women learned to play with other women, most North American players learned to play with men. Consequently, North American players were bigger than European players and used to playing a rougher game. This added to the already significant mismatch between the squads.
After this tournament, the International Ice Hockey Federation disallowed bodychecking in women's ice hockey. It is currently an infraction punished with a minor or major and game misconduct penalty.
In addition, the intermission between periods were twenty minutes instead of fifteen. This has since been abolished and changed to the usual fifteen minutes.
Read more about this topic: 1990 IIHF Women's World Championship