I don't claim to have any real biomechanical or kinesiological knowledge or background. A recent discussion about FA pitchers, the horror show of 2012 and pitching injuries ignited my desire for a slightly deeper understanding of why pitchers get hurt, I wanted to understand what an Inverted W really meant and why they call it an inverted W and not an M. Thanks to Google Analytics I found myself at Blue Jay Hunter (instead of a NSFW site describing a Golden Gate) where a commenter posted a link to Chris O'Leary's website.
I found this website to be an interesting read. He shows the difference between the deliveries of Greg Maddux and Mark Prior that many scouts missed. It was actually very subtle and could only be spotted in a frame by frame analysis.
If you want to copy pitching mechanics then according to Chris it would be best to emulate Greg Maddux, Roger Clemens and Tom Seaver. Conversely stay away from John Smoltz, BJ Ryan and Mark Prior.
Not all pitchers with the inverted W will be injured. The chances of injury increase with the velocity that the pitches are thrown. According to Chris, Tom Glavine is an example of that.
This list seems to be almost on the money. Most of the pitchers he flags for arm injuries have had major arm issues including Kyle Drabek.
Looking at his analysis, I am not surprised that BJ Ryan's career ended so badly. He was the bad boy of bad pitching mechanics. Anthony Reyes and his extreme inverted W is another poster child for pitching injuries.