I would say that injury can be avoided with any marching style by using proper upper body control. If you are engaging your core muscles and lifting up out of your hips, it limits the stress put on your knees and ankles. Lifting from the upper body will allow you to accept the ground with your feet as you roll through, where a soft upper body will force your weight down into the ground. Not only does this cause a lot of trauma for your knees and ankles, but it creates that oh so wonderful pulsating sound on sustained notes. When you see a group that has exceptional training in body control, they have that illusion of gliding along the top of the grass regardless of the technique they are using. I think this is why many groups are utilizing ballet type excercises in their basics programs now. Dancing requires you to be very light on your feet and the training dancers use really focuses in on the core muscles to control that. And of course with that added vocabulary, the dancing was bound to be incorporated into the field shows.