going over the hurdle is not as big as an issue as you think. i know a kid who does the 300m hurdles, and he literally long jumps over them and runs 38 seconds. the main issue is making sure you don't stop when you go over the hurdle. The first step you take, when your lead leg comes down, leads to continue driving into your sprint. your trail leg also needs to come around quick, but as long as you don't lose your speed, you'll be fine.
