Hey guys I'm new here. I know ASMI has done a lot of research in baseball injuries.
Has there ever been a study on all significant injuries in the MLB?
I have the hypothesis that the main reason for increased injuries is increased velocity in the MLB but I cannot prove this. I could be wrong on this one.
How are the injury rates when you compare soft tossers (87-90) with fireballers (93+). do injuries occur more often with hard throwers? I would asume that higher velocity= more torque on the joints but I don't know if that makes a difference.
I think such an analysis to see if there is a correlation between velocity and major injuries to the arm (UCL, bad shoulder injuries-I'm not talking about minor soreness or something here but real season ending injuries or at least injuries that at least cause several months off time).
Kinetics Related to Pitch Velocity: By Ben Hansen and Timothy Evans [ASMI Summer Researchers]
To answer your second question, Yes! As a person throws faster, the kinetics (i.e. forces and moments) seen by their joints increases. However, this occurs on a per subject basis. For instance:
“Pitcher A throws two pitches. The first pitch is 80 mph and the second pitch is 85 mph. The second and faster pitch would in turn result in increased forces and torques at Pitcher A’s shoulder and elbow.”
However, do fast throwing pitchers always place more stress on their elbow than slower pitchers? Not always. Consider the following:
“Pitcher A throws 85 mph and places 60 Nm of torque on his elbow. Pitcher B throws 90 mph and places 55 Nm of torque on his elbow. “
This case can occur, and it sometimes does. It really depends on a pitcher’s mechanics. Although, in general, faster throws by an individual result in increased torques and forces, some pitchers are more effective in their delivery and can throw harder with lower torques and forces than others. This is not always the case.
To answer your question regarding studies that have quantified this relationship, a recent pitch speed study was conducted by Dr. Jason Long et al in April of 2012. (Abstract: 2012 Great Lakes Biomedical Engineering Conference)
The authors reported that on a per subject basis, internal rotation torque, elbow valgus torque, and anterior shoulder shear force follow a linear relationship (R2 = 87.2, 81.3, 90.0 respectively) with pitch velocity. Thus, a pitcher who progresses to throw faster will generate increased forces and torques on his arm.
Still, each pitcher is different. Some pitcher’s linear trend lines of force versus pitch velocity had tremendous slopes while some others have rather flat slopes. By this, I mean that some pitchers are able to throw at increased velocities with less change in their kinetics than others.
You also seem to ask if there is a link between force/torque levels and arm injury. To answer this it is first important to understand the anatomy we are dealing with. The stabilization of the elbow joint is achieved through the joint capsule, muscles, and ligaments associated with the joint. The most popular anatomical feature, especially in baseball, is the ulnar collateral ligament (UCL).
The UCL was determined to contribute to 54% of the stabilization of the elbow joint during valgus stress (Morrey et al). In addition, ASMI reports a maximal average of 64 N-m of valgus torque experienced by the elbow during the throwing motion. Thus, 34.6 N-m of torque (54% of 64 N-m) is imparted to the UCL each time someone throws the ball.
Similar testing of cadaveric elbows by Dillman et al have shown that the UCL fails under 32 Nm of valgus torque. This is one of the few quantitative reference values for limits of the UCL. Moreover, it suggests that a pitcher's elbow is near its maximum capacity during the throw.
Having said that, the muscles surrounding the joint are also contributing to its stabilization. Depending on a player’s personal strength and flexibility these muscles aide in the support of extreme valgus torques.
As well, when a pitcher becomes labored, his muscles become more fatigued and improper mechanics ensue. This makes the pitcher more susceptible to injury of the UCL when throwing. So even though the short answer to this question would be “yes,” the more correct answer would be that an arm injury is a multifactorial occurrence that is the result of many different events occurring simultaneously. In time, this will overload structures in the elbow that are not built for the stress placed upon them.
Also, you asked if there were any studies performed in regards to all significant injuries in the MLB and here is a study that may interest you. I’m not sure if this is what you were looking for, but I’ll summarize it a bit for you.
The number of players on the disabled list has increased over the past eleven years. Pitching injuries were the most common and elbow injuries showed the most increase in occurrence over the 11 years. It is also reported that elbow and shoulder injuries make up ~50% of all injury reserve in the MLB.
To reiterate, there is a strong relationship between injury and kinetics in the pitching arm. Likewise, there is a large link between pitch velocity and kinetics. However, there have not been any direct studies relating pitch velocity and arm injury in the MLB.
References:  Long, Jason; Hansen, Ben; Raasch, William “The Influence of Pitch Velocity and Throwing Distance on Upper Extremity Biomechanics” [abstract] - Great Lakes Biomedical Engineering Conference - April 2012  Fleisig, G; Barrentine, S; Zheng, N; Escamilla, R; Andrews, JR. “Kinematic and kinetic comparison of baseball pitching among various levels of development” - Journal of Biomechanics - 1999 32:1371-1375  Morrey, B; An, K; “Articular and ligamentous contributions to the stability of the elbow joint” - American Journal of Sports Medicine - 1983 11:315-319  Dillman, C; Smutz, P; Werner, S "Valgus extension overload in baseball pitching" [abstract] - Med Sci Sports Exer - 1991 23:S135
I wanted to bring the following article to your attention:
Bushnell, B; Anz, A; Noonan, T – “Association of Maximum Pitch Velocity and Elbow Injury in Professional Baseball Pitchers” – The American Journal of Sports Medicine (2010) – Vol. 38, No. 4, 728-732
Bushnell et al recruited 25 MLB Pitchers in the Cactus League in 1998 (21 RHP and 4 LHP). They then followed these pitchers for 3 years. Of the 25, 9 sustained elbow injury. Three of these injuries required Tommy John Surgery (UCL Reconstruction). The non injured group threw the ball 85.22 ±3.24 mph and the injured group threw the ball 89.22 ± 5.36 mph.
Workload (pitch counts and innings pitched per season) was also analyzed; however, there was no statistically significant association between workload and injury. There was a significant difference between career length in the two groups. The injured group outlasted the non-injured group by 3.2 years. This goes to show that faster throwing pitchers are(in general) more desired and have a greater competitive edge than slower throwing pitchers.
The study was limited, however, in that the sample size is very small and that we know nothing of how these pitchers were selected (i.e. they were not necessarily randomly selected). This data was also gathered almost fifteen year ago. There is a reason why it was not published earlier..
Ben, Well answered. I can't really add anything to your treatment of the relationship between velocity and injury. However, one has to ask if the assumptions in the original poster's question are valid.
1. Has the velocity of MLB pitcher increased? I think so but it is difficult to prove given the differences in how velocity has been recorded over time. (Radar guns of various types, Pitch F/X and changes in assumptions on Pitch F/X) Regardless, I don't believe the velocities have gone up all that significantly.
2. Are injury rates up for MB pitchers? I'm not sure that's the case. It may be possible that we are simply better at diagnosing injuries.
“1. Has the velocity of MLB pitcher increased? I think so but it is difficult to prove given the differences in how velocity has been recorded over time. (Radar guns of various types, Pitch F/X and changes in assumptions on Pitch F/X) Regardless, I don't believe the velocities have gone up all that significantly.”
You pose a great question here, but make it difficult to answer! I couldn’t find any solid peer-reviewed journal articles tracking the trends of MLB Pitch Velocities; however, there was a nice article in ESPN Magazine not too long ago called “The Age of the Pitcher” (http://espn.go.com/mlb/story/_/id/8048897/the-age-pitcher-how-got-here-mlb).
They (Jason Stark - ESPN), posed the same question as you and set out to answer if pitch velocity has increased in the MLB. They consulted with Inside Edge and report that the fastball has increased from 90.2 mph to 91.2 mph since 2005. I guess that’s about the same as a climate change due to global warming (+1.4 Degrees F over the past 100 years). It’s a small but subtle change. Yet again, we have to question the accuracy of this data. Another stat they report: the number of pitchers throwing over 95+mph has increased steadily from 2007 to 2011 (11 to 35, respectively). There’s some other neat stats in that espn article that you’ll find interesting.
“2. Are injury rates up for MLB pitchers? I'm not sure that's the case. It may be possible that we are simply better at diagnosing injuries.”
Here’s some hard evidence from a peer-reviewed paper by Posner et. al. They investigated the epidemiology of baseball injuries from disabled lists in the MLB from 2005-2008. They report a 37% increase in injuries to all MLB baseball players over this period. Pitchers experienced 34% higher injury rates than fielders. Also, injuries were the highest in April (5.73/1000 exposures) and lowest in September (0.54/1000 exposures).
My opinions: 1) Faster throws lead to increased joint torques. Increased joint torques lead to an increased risk of injury. 2) The fastest pitchers are throwing faster than they have in the past 5-10 years (slightly). 3) Because of (1) and (2), there are more injuries to pitchers than in the past 5-10 years.
Caution to my opinions:
4) The method of how we diagnose injuries is most likely the same; however, teams are more careful with their expensive athletes. Pitchers are no longer throwing ridiculous amounts of pitches per game, and players are most likely being placed on the disabled list as a precaution. I feel like this is the case because the # of players on the DL is highest in April and lowest in September. Teams are more cautious early on because there's SO much baseball to be played. Teams are less cautious with their players during September because they are nearing the end of the season and are competing for a chance to play in October. More-so than the Team, the players don't want to be on the DL when they can help give their team a chance to make the playoffs.
You can’t say that baseball in September isn’t the greatest time of the year!
References:  Stark, Jason ““The Age of the Pitcher” (http://espn.go.com/mlb/story/_/id/8048897/the-age-pitcher-how-got-here-mlb). Posner, M; Cameron, K; Moriatis Wolf, J; Belmont Jr, P; Owens, B; - “Epidemiology of Major League Baseball Injuries” – The American Journal of Sports Medicine (2011) – Vol 39, No. 8, Pgs 1677-1680  Bradbury, J; Forman, L; “The Impact of Pitch Counts and Days of Rest on Performance Among Major League Baseball Pitchers” – Journal of Strength and Conditioning Research(May 2012)– Vol 26, No. 5, pgs 1181-87.
"...I don't believe the velocities have gone up all that significantly."
Interesting question, especially with the handling of pitchers differently than in the old days. Today's MLB pitchers know they will be relieved earlier in the game than before. Therefore, they pace themselves to that end rather than either a complete game or later in the closing innings. They can put more energy into each pitch knowing that. Perhaps this could account for a greater velocity.
Another factor is that many MLB pitchers come on board with preceeding injuries from overuse at a time that their growth centers were still not closed.
Humans have not evolved that much over the time frame that baseball pitching has been around. True, they are bigger and stronger but this is more likely due to better nutrition and less ongoing illness than before. I have not heard anything about ligaments and tendons being stronger than in earlier days. Muscles, yes with weight rooms etc. But not ligaments and tendons.
You can only tune up a VW car to a certain peak and that is it. Just not designed for any more.