Pitching Mechanics Analysis
Scott Williamson is a pitcher who, like Mark Prior and Kerry
Wood, started out with tremendous
promise but whose career was derailed after two years by arm
problems. That includes Tommy John surgery after his second year
and shoulder problems more recently. Let's
see if we can figure out what happened.
Arm Action And Timing
A pitcher's arm action and timing are the primary
determinants of the long-term health of their arm,
so it's always the first thing I look at. As the clip below
demonstrates, Scott Williamson's arm
action is problematic.
The issue is that, like Chris Carpenter, BJ Ryan,
and Kerry Wood, Scott Williamson has a major
Inverted L in his arm action. This ruins his
timing and is the root cause of his elbow and shoulder problems.
Scott Williamson's Inverted L
Scott Williamson's Inverted L is easier to see
in the still photo above. The thing to notice is how his Pitching Arm Side (aka
PAS) elbow is at the level of his shoulders and his PAS forearm
is hanging down vertically beneath it. This will increase the
distance over which, and the force with which, Scott Williamson's PAS
upper arm will externally rotate, which will put significant
stress on both his elbow and ultimately his shoulder.