Must Watch...
This is a must watch. It is probably more in-depth than what you may normally hear from an elite level baseball player. Josh is an extremely mobile, strong, fast-twitch, and intelligent athlete, so it is important to keep in mind that building a swing as good as his takes a high level foundation.
He says "every movement has a purpose and a function." Those movements have to be timed, rhythmic, and he has to maintain dynamic balance of the posture of every joint that is in action. Notice he will mention clearing his front foot open to initiate hip/shoulder separation. The other notable phrase he mentioned was "stretching his rubber band" to achieve maximum bat-speed.
If motor learning has taught us anything, it is that the body will organize itself based on the ultimate goal. If the ultimate goal is well timed aggression (bat-speed), we will ultimately yield more valuable swings over time. With proper training of "intent" and an ability to recognize pitches, make adjustments when necessary, and use movement for timing/energy, we can build athletic hitters who express bat-speed.
Enjoy the video.