The concepts of these kinds of “thumps” on certain body points are routed in Qi Gong. I used to practice these kind of exercises on a regular basis and found them to be rejuvenating overall. They say the thymus tap will result in a tingling sensation and feelings of joy.
Read the link below for a more thorough explanation of what to do, but the general gist is depicted above. Let us know if it works for you!