The gluteus maximus is the larger muscle located around the hip and buttock area which effectively allows you to rotate. Exercises in this video include things a simple as the lifting and dropping of the pelvis which builds up the gluteus maximus muscle. Stepping exercises place pressure on the knee through to the gluteus maximus. Increasing the step height, onto a box or some other surface, places further pressure on the hip muscle thereby building it up. As with many exercises, if you are able to maintain a high degree of flexibility and strength within the hip, able to rotate left and right, this will also help in later years.