A rotator cuff tears isn't a death sentence for a pitcher's career, but it's far from a positive prognosis.
Baseball pitchers and rotator cuff problems seem to go hand-in-hand despite the rotator cuff being much smaller than other muscles about the shoulder and upper back. The four small muscles that make up the rotator cuff are vital to the shoulder’s health and to a pitcher’s playing career. In fact, at one time, rotator cuff surgery was considered a career-ending sentence. That isn’t the case any longer, but it still hasn’t reached the level of relative certainty of ACL surgery or even Tommy John surgery. Without a healthy rotator cuff, a significant cascade effect culminating in shoulder instability and/or tears of the labrum is possible, if not inevitable. In today’s episode of Collateral Damage, we will be looking at the rotator cuff and ways of treating it in all of their complexity.
The rotator cuff is made up of four muscles that attach at different sites on the scapula, a.k.a. the shoulder blade. These four muscles are known as the supraspinatus, infraspinatus, teres minor, and subscapularis. The main function of the rotator cuff as a group is to ensure that the humeral head stays centralized in the glenoidfossa. This cannot be emphasized enough. Two of the muscles—infraspinatus and teres minor—assist in external rotation of the shoulder, while the subscapularis is the only rotator cuff muscle whose role is as an internal rotator. The supraspinatus also assists in abduction, especially early in the motion. Without that rotator cuff, the humeral head would slide all over the place and tear up the labrum, articular cartilage, and other tendons in the area.
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Kicking off a series on the most most frequently suffered baseball injuries with a look at a common shoulder complaint for pitchers.
This article on impingement kicks off an in-depth series on some of the most common injuries we see in baseball. While impingement is an official diagnosis, it describes a dynamic process or a collection of conditions rather than a single end result, such as a torn ACL. Complicating matters for the fans is the fact that the end result is what is usually reported. Pedro Martinez and his case of rotator cuff inflammation, which developed into a partial rotator cuff tear? Impingement played a role. Martinez is an extreme example of how shoulder impingement can derail a career, but how many times have we heard of a pitcher developing rotator cuff inflammation and spending more time on the disabled list than expected?
Brief Anatomy There are actually four different joints that make up the shoulder complex: glenohumeral, scapulothoracic, acromioclavicular, and sternoclavicular. Each of these must be functioning properly in order for the shoulder to function normally while performing baseball activities. The sternoclavicular (SC) joint is the only joint connecting the shoulder to the axial skeleton. The medial end of the clavicle attaches to the sternum with a cushioning disc between them, much like a meniscus, which provides a very strong connection that takes a large amount of force to injure. The joint is further strengthened by very strong ligaments. The other three joints are the ones we are most concerned with when discussing impingement.
Cashner gets disabled, Dunn gets an appendectomy, and Escobar becomes the first potential visitor to the 7-day DL.
We mentioned on Wednesday that the injury front had been quiet, but as we expected, things picked up (or broke down) between then and now, giving us plenty to cover. Unfortunately for Cubs and White Sox fans, much of that activity came at the expense of Chicago-based players.
One of the leading medical authorities on shoulders talks about advancements in that area.
There are only so many "super surgeons" in sports. While everyone knows Dr. James Andrews and Dr. Frank Jobe, fewer know about Dr. Neal ElAttrache. ElAttrache is the Director of Sports Medicine at the world famous Kerlan-Jobe Clinic and the team orthopaedist for the Los Angeles Dodgers. He might be best known today as the surgeon who rebuilt Tom Brady's knee in 2008, but ElAttrache is also at the forefront of research in baseball. Along with several doctors, including Jobe and Dr. Lewis Yocum, ElAttrache has just published a studythat will help physicians understand the arms of athletes better through a new testing protocol. In a recent conversation recorded for Baseball Prospectus Radio, I had the chance to ask ElAttrache more about his study and the state of the art in sports medicine.
Between a careful analysis of what data is available, the creative use of proxy variables in estimating injuries throughout time, and the application of some principles of sports medicine, we are at least in a position to make some educated guesses about the nature of pitcher injuries. Our particular focus in this article will be the progression of pitcher injury rates by age.
Pitching is an unnatural act that invites injury. The stress it places on the bones of the shoulder, arm, and back is immense. The strain it places on the 36 muscles that attach to the humerus, clavicle, and scapula is remarkable. It is widely accepted by sports medicine practitioners that every pitch causes at least some amount of damage to the system.
It seems fair to say that the study of pitcher injuries is an important part of sabermetric analysis. The statistical evidence available to test theories about pitcher injuries, however, is often missing. While there are databases that contain every recorded statistic from the days of Al Spalding and beyond, and others that document every play of every game in the past 30 years, a comprehensive database of player injury history simply doesn't exist.
However, between a careful analysis of what data is available, the creative use of proxy variables in estimating injuries throughout time, and the application of some principles of sports medicine, we are at least in a position to make some educated guesses about the nature of pitcher injuries. Our particular focus in this article will be the progression of pitcher injury rates by age.
Methodology and Statistical Results
To create an actuarial backbone for our study, we applied the same approach that is used to calculate attrition rate in the PECOTA forecasts. Attrition rate describes the percentage of pitchers who experience a decline in their innings pitched of at least 50 percent. Such a dramatic decline will not always indicate that a serious injury has occurred--it can also reflect demotion, retirement, and so on. However, by placing a few restrictions on our dataset, we can serve to limit these cases, and use attrition rate as a reasonable proxy for catastrophic injury.
In order to be included in the study, a pitcher needed to have pitched at least 150 innings in the previous season, with a park-adjusted ERA no more than 10 percent worse than his league average. That is, our study was focused on pitchers who had already pitched at least one effective season in the major leagues, and who were likely to have every opportunity to do so again in the absence of significant injury. All pitchers from 1946-2002 were considered, with innings pitched totals prorated over a 162-game schedule. The chart below tracks attrition rate at different ages throughout a pitcher's career.