I like to bump into the shoulders of women in my school as hard as I know i can get away with.. The idea is even though it doesn't hurt that much if done properly it leaves your opponent discombobulated and wondering if the impact was intentional or not as well as unable to do anything since their assailant has been walking away the whole time.. to deal maximum damage I put my arms out at my sides, flex them to keep them steady, start speedwalking and this is when the magic happens. The trick is to bump into the shoulders of people in the halls who are walking in the opposite direction of you. because that allows you to do the most important thing of all: when you're walking people expect you to move out of their way. You don't have to swerve to hit people all you have to do is walk in a straight line which makes them hit you. It may even provide some legal protection since neither of us moved and we both walked into each other.