Monday, July 30, 2012
Chris Sale and “dead arm”Posted by Kyle Boddy
In mid-May, I wrote about Chris Sale's faulty elbow and discussed valgus stress in the elbow as it relates to sidearm pitchers. Now there are reports that Sale will be shut down for a start or two due to "dead arm." Well, I bet many of you are asking...
What is dead arm, anyway?
Dead arm is the catch-all diagnosis for a pitcher who's losing velocity and/or command of their pitches, blaming it on fatigue. Physiologically, there's not much to this diagnosis - it's a description of symptoms rather than an actual inspection on the root causes. Chris Sale's velocity has been steadily dropping over the year:
It's also worth noting that Sale threw all of 71 innings in 2011 out of the bullpen, and in 2012 he's already at 124 innings split between the bullpen and in the rotation (predominantly in the rotation, of course).
We've talked about how sidearmers are more susceptible to valgus stress due to their mechanics, and this can play a role in the so-called "dead arm" issues that pitchers experience. As pitchers throw more and more innings at game intensities, three major physiological changes occur:
-They tend to gain external rotation range of motion around the shoulder joint and lose internal rotation at the same time
-The muscle tissues in the forearm develop adhesions as they are stressed while stabilizing the pitching elbow in the delivery
-The ulnar collateral ligament (UCL) can become stretched out while holding the bones of the arm together
The first two are all but guaranteed to happen, while the third happens if the pitcher has improper force application technique (mechanics) or other issues that can lead to a UCL sprain/rupture.
Most knowledgeable trainers will stretch their pitchers into internal rotation and provide exercises that passively engage the external rotators of the shoulder to help restore ROM in IR and strength in ER without a concomitant "bounce" that happens in the late-cocking phase of the delivery to help mitigate issues with the first physiological change.
A pitcher (me) about to exit late-cocking phase
Forearm adhesions and soreness can be treated with myofascial release using items like The Stick, foam rollers, static stretching, and manual therapy from athletic trainers.
There's not much that can be done with the last change - if your UCL is being stretched or gradually torn due to poor mechanics, that requires a mechanical change and better attention to pitching arm fitness. Performing specific exercises that improve forearm rotation near the time of ball release will help, though the only real way to know is to use high-speed video to perform a biomechanical analysis on the pitcher in question to get valgus stress levels before and after changes are made to verify things are going in the direction the coaches and trainers want.
So... what's going to happen down the road?
Only the White Sox can determine how to approach this particular case. While shutting down Sale for a few starts and getting him going again sounds like a good idea, pitching isn't an activity that is easily dropped and picked up again - even if Sale's throwing bullpens and simulated games, competing in a game is a completely different activity. Pitchers throw with more intensity and cause more stress to their arms when pitching in competitive games compared to when throwing on the side - this has been verified time and time again with results being published from various biomechanical labs.
While Keith Law isn't high on Chris Sale's mechanics from the standpoint of a starting pitcher, with a guy this good, it's hard to keep him in the bullpen if he can show this kind of dominance in the starting rotation. I'd keep him in the rotation, limit his innings this year (fat chance given the AL Central playoff race), and work on slight tweaks in the off-season to address mechanical issues and build strength in his pitching arm in hopes of mitigating issues down the line.
One thing's for certain, though: Sale's precipitous drop in velocity is a real problem and highly indicative of some sort of injury to the pitching arm. Just because he's not reporting pain doesn't mean he's not injured - plenty of pitchers throw while injured though they display no symptoms.
Kyle Boddy is the owner of Driveline Baseball and Driveline Biomechanics Research, both in Seattle, Washington. At his facility, he's melded statistical analysis, strength & conditioning, prehab/rehab, and advanced biomechanical analysis concepts to develop improved efficiency, durability, and fastball velocity of baseball pitchers. He can be reached via email at firstname.lastname@example.org and found on Twitter: @drivelinebases.