The previous post seemed a little unusual. I have no idea what was meant by success being a function of skeletal alignment. I find that firing success is a function of sight alignment. Skeletal alignment is going to be ever-changing in the fluidity of a person on the move. You can limit the motion of some aspects, but for everything that is locked up, the more motion is impeded.
Later, the statement is made that in real world, you want to be moving and shooting instead of being a stationary target. Advice like that is often given out as if it is some sort of fact when it is not. It may be quite foolish to leave cover so that you will be on the move while shooting, for example.
I am not sure of the value of teaching a person to shoot a shotgun with slugs from the hip at 25 yards. It is a neat trick and that is all that it is unless the kid trains very regularly with this unsighted method, like weekly. I don't doubt it can be done, but I also don't doubt that the first time that student tries to repeat that drill outside of class that he is going to have an overly high percentage of errant rounds that fail to hit the target and potentiall fail to be stopped by the backstop. A 12 ga. slug is a very dangerous projectile to lose track of while firing from the hip. Since talking real life here, then what is the situation where you will be moving with your 12 ga. shotgun and shooting targetst at 25 yards? Let me guess. It is where you are carrying a fallen comrad over your shoulders and your opponent has his back up against a tall bluff face. The reason you are closing distance on the opponent is because he guards the secret stairway to the top of the bluff and you need to access that stairway right away in order to get you and your fallen comrad out of the immediate area before some more significant or larger lethal threat acts on the situation, such as the time bomb that will go off at any second. How am I doing?
Shooting on the move involves a lot of variations human bipedal locomotion has a lot of variation ranging from slow walking, fast walking, jog, trot, and sprint. It may be forward, lateral, or backwards. It will be heavily influenced by terrain, obstacles, and other environmental conditions. People have success with the bent-knee crouch walking while shooting, but often are unable to attain needed speed and have trouble adapting the technique to uneven terrain or small ostacles.
Surprisingly, a lot of people are fairly good shooters if they simply forgot all the SWAT things they have seen on TV and simply walk normally while shooting. The problems here are that the person presents a larger upright target, is also fixed into a given speed, and usually has problems negotiating obstacles while shooting. The advantage is that it can be used more effectively and with less mental stress by a person who doesn't practice every week with the local SWAT team.
I did check out the site, but I am not ordering the video. I liked the page that showed the "impossible" things that can be done with a shotgun. I have no doubt a 240 man can shoot a shotgun rapid fire while standing on one foot, or do it while sitting in a chair with his feet off the ground. The use of terms like "impossible" usually implies some sort of miracle facet to such methods. They come and go, always promising great things, but few ever command anything but a tiny following.
I liked the fact that his technique is the only "bio-mechanically correct" shooting technique. In other words, Turnipseed is the only prophet by which a shooter can get to shooting nirvana. This is one of those sorts of phrases that is a non-falsifiable techno jargon statement that is meant to sound really impressive, and it does, but has no actualy value or meaning. I don't believe Turnipseed is a medical doctor or Ph.D. working in biomechanics. If he is, he failed to list these credentials. There is no defined or recognized criterion of what is or is not biomechanically correct when it comes to unnatural behaviors such as shooting a gun. Turnipseed may have a fairly ergonomically positive technique, but being ergonomic does not mean that it is biomechanically correct.
It may be a nifty thing to learn, but each of the 'new' shooting methods that come out usually have some beneficial aspects, some that don't seem to make any sense at all, and generally die of with time or get portions adopted into mainline techniques, but are rarely taken full bore. They never get taken full bore because they don't actually live up to the all the claims and hype.