In every Sport it occurs, its down to Biomechanics, posture of movement it can and is trained. A lot of the time your pychodinamics , History of movement and why, gets in the way. Punching Hard is down to the posture of Mind and Body working together in technique. Power is caused by Pushing back, not forward, simple. Yet not many people understand the Lever system we have. Im oldschool thats where I got my Base, somebody show me something that makes sense, I will listen[ Had a few of them in my time]. Its all down to the Position of your Botty getting Maximum Power. So the Orchestra doesnt Hit a Bum note.