laflippin,
Well to hear that people are teaching pronation is disheartning . What I've read sounds plausable and I do agree that the curve has been taught with the palm-up which just hurts thinking about it.A good illustration of pronation is a picture of a quarterback after he releases a football. Which does occur naturally, too bad its being exploited .Okay so now lets take an image of the going ons that you have explained of a curve being thrown and add too it a tilted body and head which raises and seperates further away from the body .Which puts a tremendous amount of strain on an isolated elbow. I believe by correcting the tilt your elbow has larger muscles ie. shoulder, chest helping stabilize and deliver the ball which relieves some of the burden on the elbow. I believe this should happen on all pitches. Imagine holding a large paint brush in your hand full grip and paint a wall in a downward direction to me thats a curve ,if you turn the brush down and inward using your wrist halfway down your brush stroke to me thats a slider. Im interested on hearing your sources. All the best Rich