Another way you can practice this in Hsing-I is to use the fists as a progression working deeper into the body ultimately back into the organs.
So, Pi Chuan emphasizes the opening and closing in the hand. Tsuan Chuan adds and emphasizes the opening and closing of the elbow. Beng Chuan adds and emphasizes the shoulder. Pao Chuan adds and emphasizes the ribs. Notice how the design of the movement of Pao Chuan is exceptional for getting all parts of the ribs including the sternum, sides, and back. In Heng Chuan, you are going to add the crosses, legs, and really get to the opening and closing of the organs, but you can practice this by breaking it down further over time as well.