Boot camp has also been stressing a "program", which cuts down on injuries and helps skaters "own" the skills they are learning. We've worked a lot on muscle memory and physical fitness along with skill-building. I've learned a lot about blocking. Anyway, the title of this is really "Booty Blocking" but I heard one of the boot-campers say this in admiration of another skater's great booty blockin' butt and it sounded like a better title! When done properly, booty blocking will cause you quite a few hits to the back, hopefully drawing a penalty for your opponent or at least causing her to break her momentum. The proper posture for a booty block is to get low and wide, forcing your opponent to get as close to you as possible, but giving her no room to maneuver around you without hitting you from behind (a big no-no in derby). Knees are bent more to absorb such a hit, elbows are tucked in and forearms are resting on your upper thighs for balance. Your feet are more than shoulder width apart so as to take up as much space as possible while giving you a stable base that's not so wide that it will result in a low block penalty. Your eyes are looking over your shoulder for the hit that is inevitably coming.
The booty block is best done when you are holding the inside line to prevent a jammer from getting by you and/or your teammates. You are not picking your feet up, but are self-propelling by either slaloming or by weaving your feet to maintain a decent speed. Ideally, you use your left foot to "feel" the edge of the track or use your peripheral vision out of your left eye to make sure you are holding that inside line.
Some common mistakes are: giving up the inside line in the turns by coming off the line too much (even an inch can be too much depending on your opponent); getting your stance too wide and planted so that you cannot react and regain your derby stance when an opponent hits you from the side or a jammer gets past you; and misjudging a hit and swinging your arms causing you to hit your opponent. Roller derby is not about roller skating because it is not a leisurely jaunt around the rink and most of the time, unless orchestrating the booty block, you should find yourself only on one skate!