NEW YORK — A yearlong study by Major League Baseball concluded rising velocities, pitch shaping and emphasis on maximum effort are the likely causes of the vast increase in pitcher injuries and recommended exploring rules changes to address the problem.
The 62-page report released Tuesday said the trends extended to high school and youth baseball because of the incentive to get noticed by professional scouts. The study said there is no evidence linking the pitch clock to injuries.
Illustrated with 26 tables of data, the report was based on interviews with more than 200 people that included players, front office executives, orthopedic surgeons, athletic trainers, physical therapists, biochemists, major league, college and independent coaches, and international trainers.
“This is a landmark event,” said Glenn Fleisig, director of biomechanics research at the American Sports Medicine Institute in Birmingham, Alabama, who participated in the study. "This is a very important first step, which is to identify the problem and identify the likely risk factors. I am pleased that there was such a consensus. ... The next step is to do various types of research studies."
Possible areas to be studied include offseason training and early season workload, non-game activity, defining and measuring fatigue, biomechanics and pitching style, obtaining more data from international leagues and differentiating results from domestic and international signings.
Major league pitcher IL placements increased from 212 in 2005 to 485 this year and days on the IL rose from 13,666 to 32,257.
“The most significant causes are likely the increased velocity of pitches, the emphasis on optimizing ‘stuff’ (a term referencing the composite movement characteristics of pitches, including horizontal and vertical break and spin rate), and the modern pitcher’s focus on exerting maximum effort while pitching in both game and non-game situations,” the report said.
“Some experts speculated on the potential influence of other factors on the short-term increase in injuries over the past several years, including the lasting effect of COVID-impacted seasons, the introduction of the pitch clock and perceived inconsistencies in the surface grip of the baseball. There was not sufficient consensus or evidence to establish a link between these other factors and pitcher injuries.”
The report said experts recommend MLB consider rules changes to “increase the value of pitcher health and durability and decrease the value of short-duration, max-effort pitching.”
“For instance, playing rules could be adjusted or designed to encourage or require starting pitchers to preserve enough energy to allow them to pitch deeper into games,” the report said. “These incentives could be supported by roster rules that more appropriately regulate the availability of pitchers on a roster or in a team’s bullpen for a given game, including potential changes to the number and frequency of transactions that allow clubs to replace pitchers on their rosters.”
MLB experimented in the Atlantic League with a double-hook designated hitter from 2021-13, in which a team lost its DH if its starting pitcher didn’t finish at least five innings in the last two seasons. MLB lowered the maximum on pitchers from 14 to 13 on June 20, 2022, though it is 14 from Sept. 1 on after rosters expand from 26 to 28. The minimum pitcher IL was restored to 15 days in 2022 after dropping to 10 for the previous five years.
Factors in injuries may include use of weighted balls in training, increased intensity of bullpen sessions, a possible decline in cardiovascular and endurance training, and workload management that incentivizes harder effort over shorter spans.
“Multiple medical experts described new injury patterns that they believe are tied to the focus on velocity and max-effort pitching,” the report said, listing latissimus and teres major tears, rib fractures and oblique strains.
Among the data points:
- 1. Tommy John surgeries for major and minor league players increased from 104 in 2010 to a peak of 314 in 2020 and declined to 281 this year. Among those this year, 41 were in the major leagues or on minor league rehab assignments and 240 were with minor league clubs.
- 2. Since 2008, average mph velocity in the major leagues has risen from 91.3 to 94.2 for four-seam fastballs, 82.8 to 84.6 for sliders, 75.7 to 79.5 for curveballs and 81.7 to 85.5 for changeups. During that period, fastball usage declined from 60% to 48%. By comparison, fastball velocity in Nippon Professional Baseball was 91.1 this year.
- 3. IL days for pitcher elbow injuries rose from 3,940 in 2005 to 12,185 this year and for shoulder injuries increased from from 2,634 to 5,445.
- 4. IL placements from spring training through opening day rose from 61 in 2017 to 112 this year and from day two through the end of the regular season from 303 to 352.
- 5. Starts of five or more innings dropped from 84% to 70% in the majors from 2005-25 and from 68.9% to 36.8 in the minors.
- 6. Thirty-five players selected in the top 10 rounds of this year's amateur draft had Tommy John surgery, up from four in 2005.
- 7. Prospects who threw 95 mph or higher at the Perfect Game National Showcase increased from three in 2018 to 36 this year.
- 8. UCL surgeries among youth and high school pitchers at the Andrews Sports Medicine & Orthopedic Center rose from 10% of all UCL surgeries in 1995 to 52% in 2021before dropping to 42% in 2023.
- 9. Pitchers per team during the season averaged 15.1 in 1980, rose to 34.4 in 2021 and declined to 32.5 this year.
- 10. International players had more UCL surgeries than domestic counterparts in 2023 for the first time since 2010.
- 11. Average innings over the previous season for college starting pitchers selected in the first three rounds of the amateur draft dropped from 101 1/3 in 2012 to 74 this year.
- 12. Pitchers selected in the first three rounds of the draft fell from 73.3% in 2014 to 41.7% this year.
