Improving performance in rotational sports, such as hitting and throwing, demands effective use of specific core muscles. Effective use of these muscles can automatically increase body torque, bat or arm speed, and power. Ineffective use impedes attaining these desired goals. Rotational power increases with improved hip and shoulder separation. An understanding of the importance of hip and shoulder separation requires a discussion of basic concepts of body movement and anatomy. The process is complex, but an overview will provide insight into how the process works. This month’s article will explain the process of hip and shoulder separation in rotational athletic movements and its importance in hitting and throwing performance. Next month’s article will discuss the many factors leading to reduced hip and shoulder separation and how they can be overcome.