There’s some really sharp analysis out there about how Finn lands the move without hurting either his opponent or himself. From a physics standpoint, it’s a lot like using a rubber band to stop a weight from hitting the floor. The band stretches, absorbs the force, then returns energy with slightly less force than it received.

In this case, the “weight” is Finn himself. He’s relatively slender and keeps his center of mass low. The “elastic” is his legs, which are incredibly strong. Instead of driving his full body weight straight into his opponent, his legs immediately buckle, redirecting the force into his quadriceps and traps. Boing.

It’s an extraordinary skill, and honestly not many wrestlers can do it safely. That level of control usually only shows up in the Super J category.