Thanks for the great response about Joel Zumaya, folks! Let's review your input and go over what I think...

(There's also my notes on additional pitching mechanics, including stills of Greg Maddux and Phil Hughes for those not interested in Joel Zumaya. I recommend it for all readers.)

Before we get started, let's look at the picture above. Yikes. His elbow is extremely high in the W-arm position, isn't it? More of the same can be seen in the video, which many of you pointed out.

Here's the first comment I wanted to touch on, from Mitch:

His arm action (I know it is controversial), but it just depends on if you like to sacrifice velocity for health. With him being a relief pitcher, I really don’t have as much concern as I would if he was still a starter.

It is unfortunate that we see baseball pitching in this light - that high velocities come at the price of torn rotator cuffs, ruptured ulnar collateral ligaments, and other arm-related injuries. I believe that high velocities (92+ MPH) are attainable without the necessary injuries that often plague the pitchers in the MLB.

As for the comment on keeping Zumaya in the bullpen to save his arm compared to starting, that idea probably has some merit on lengthening his career and his effectiveness.

Some things that you guys thought were good:

"...he uses his legs extremely well and loads with his back leg for him to explode to home." -Colin

"...On the bright side, his gs leg doesn’t appear to lock giving him repeatable footwork (even though he appears to be driving more than striding to his balance point, maybe where a lot of those mph come from). He also has great arm speed." -Andrew

"Really uses his core to his advantage with insane hip/shoulder separation
Powerfully drives his hips forward using more of his hamstrings than his abductors (think of doing a lunge forward compared to sliding sideways, pushing off with a lunge motion will use larger and stronger muscles for added power during leg drive)
Maintains a relatively controlled front side (I personally don’t like how he brings his glove to his chest, by already having the glove hanging down below the arm, I think this is inefficient as the front shoulder has to rotate and bring the glove back above the arm in order for it to be brought into the chest)" - Mitch
I agree with all of that. Mitch makes an interesting observation when he says that Zumaya drives his hips forward using a lunge-type action as opposed to a side-step. This is something I hadn't really noticed, but it is correct. Interestingly enough, that straight-forward leg drive is what Dr. Marshall teaches his students, as they start their windup facing the batter rather than using a leg kick. In my personal experience, the straight leg drive has helped increase my velocity and helped me to keep my arm on a straight driveline to the plate, improving my control in the process.

And now, the bad:

"His elbow reaches a level higher than that of his shoulder early in the delivery where he forms the inverted W.It isn’t perfectly clear from this video, but he doesn’t appear to finish any wrist pronation." -Andrew

"…a couple things that look bad to my very untrained eye: His upper half seems to be dragging behind his legs somewhat, putting pressure on his arm to catch up through the release point. He also doesn’t clear his glove side well at all, cutting off his follow-through." -Kevin

"Beside from the injury ridden mechanics, such as the inverted W..." -Colin

"He rushes slightly as his shoulders begin rotating prior to his forearm being slightly vertical (which tends to stress the shoulder, which in turn can lead to elbow strain)His finish is ok, although there is some recoiling of his arm which adds strain to the decelerating rotator cuff musclesHe fails to keep his back shoulder over the rubber as he leads with his hips, instead he actually already has a downhill slope with his shoulders which tells me that he is not completely using his hips to his advantage
Appears to throw across his body (tough to tell by the camera angle) but this closes off his hips and works against himself. This can give greater movement/deception but also they will have to compensate by flying open early with their front side which often leads to shoulder injuries, particularly on the front of the shoulder." -Mitch

"His arm just looks uncomfortable." -Eric Cioe

"The biggest issue that I have revolves around the poor timing of his leg plant. His arm is completely behind the timing of his leg plant. Putting major pressure on the shoulder and elbow." -winabango
Here are those three frames I paused to show you the bad parts of his mechanics:

Here Zumaya has his arm in the classic W-arm position, as he takes his PAS elbow far above the acromial line. Not only does this increase pressure on the shoulder, but it often leads to...

...his arm to be late at footstrike. As winabango clearly pointed out, his arm is lagging behind at footstrike. Furthermore, his arm is still very high in a position of hyperabduction, putting major strain on the front of his shoulder. When the PAS arm gets up late, you will often see...

...hard external rotation. Though you can't see it in a still frame, when the arm is late, the arm violently "bounces" back, which puts a ton of strain on the shoulder and elbow (specifically the subscapularis and supraspinatus - two muscles of the rotator cuff group - as well as the ulnar collateral ligament). To understand how unnatural this position is, hold your throwing arm up in this position:

Now try to bend it backwards and make it look like this:

Can't do it, can you? That's because when you have your arm up in the position that Hughes does and start to drive your arm forward in your pitching motion, the inertial mass of the baseball pushes the forearm down and makes it lay back in what we call external rotation. The fact that you can't do this comfortably without applying momentum-based force should tell you something. Dr. Marshall's pitchers avoid this problem by applying horizontal force while their forearm is mostly horizontal (as opposed to applying force when the forearm is vertical, like Hughes does). This is but one component of arm action that we can incorporate into a pitcher's delivery to reduce or eliminate pitching-related arm injuries.

So, to recap, here are two major flaws you can look for when you are evaluating pitchers:

• Timing at footstrike: Is the arm up in the "high-cocked" position, or as I prefer to say, passed completely through the horizontal at footstrike?


• Position of the PAS elbow: Is the PAS elbow above the acromial (shoulder) line? It should be slightly below.

Good luck, and as always, don't hesitate to ask me any questions.