Someone watching a class at CrossFit West Santa Cruz the other day mentioned “You guys sure stick your butts out a lot.” Yes we do. In fact, we talk about sticking our butts out a lot as well. This is because the forces involved in the flexion and extension of our hips are some of the greatest of which the human body is capable. The squat, deadlift, clean, snatch, thruster, sumo deadlift high pull, even the kipping pullup, are dependent upon the opening and closing of the hips. A good coach is constantly exhorting his or her athletes to ‘push the hips back’ at the beginning of a movement and to ‘fully extend the hips’ at the top of the drive. The extending and flexing action of the hips is seen not just in CrossFit or weightlifting, but in almost all sport–the jump of a basketball or volleyball player, the hurl of a baseball pitcher, the hip throw of a judo or sambo player, a swimmer’s butterfly stroke.