Look at this video of a baseball pitcher. The principles employed are practically the same that ITF Taekwon-Do requires of its practitioners – although more subdued.
First, notice how the pitcher throws his body weight down and forward. This is what we would call the sine wave motion, going from a high position to a lowered position.
The other thing to notice is how he uses kinetic chaining, also known as sequential motion – usually and simplistically explained as “hip rotation.” The pitcher torques his body, starting from the legs, then the hips, through the spine and shoulders, and last whipping through the arm. The momentum of each segment of the body contributes to the momentum of the next part of the body.
Of course, the martial art practitioner needs to subdue such an over exaggerated motion because it exposes you at various moments throughout the motion, compromise your posture and somewhat unbalance you at the end. When the Taekwon-Do practitioner is admonished to keep the back heel flat at the end of the technique and to square the shoulders, it is in fact to ensure better posture and keep the rebound energy from not unbalancing the performer.
Now look at Randy Barnes perform a shot put. Notice how the same two power generating principles are evident, a sine wave motion and kinetic chaining. Look at the slow motion section starting at 1:00 and note how his vertical movement goes down, up and down (this is where we will punch); however, from here he is pushing the iron ball at an upward angle, so he needs to thrust his body up again. (During the entirety of his technique Barnes moves down-up-down-up.)
There aren’t any hand strikes that require us to do two rotations like Randy Barnes does for his shot put. We do have a spinning back fist strike that requires one rotation; take for instance the spinning back fist strike in the pattern Do-San, which follows the spear fingertip thrust and release (movements #6-8).
The two principles of dropping your raised body mass into your technique and using kinetic chaining / sequential motion are present in many sports concerned with speed and power generation.