Coaching staff have tried preventing injuries by placing limits on the number of innings for young pitchers, and by increasing those limits gradually each year, usually by no more than 30 innings than the previous year.
But a new study published in The Journal of Sports Medicine and Physical Fitness didn't find a link between inning limits and the risk of future injury to pitchers
"Especially in major league baseball, if people are using these to limit the amount of work a pitcher can do, there should be a correlation from these metrics to future injuries," said Thomas Karakolis, a kinesiologist with a PhD from the University of Waterloo, and one of the three authors of the study.
"We found with the entire population there was no link," he said.
Karakolis and co-authors Shivam Bhan, a former NCAA Division 1 baseball player, and Ryan Crotin, who worked as a baseball performance specialist consultant for the Baltimore Orioles, looked at pitching records over a five-year period.
All of the pitchers were 25 or younger, and had pitched at least a third of an inning in an MLB game.
The researchers included MLB records, as well as records for two minor baseball leagues, and defined an injury as any pitcher on the MLB disabled list. Karakolis estimates that 25 per cent of MLB players are injured and on the disabled list every year.
In total, the researchers analyzed over 700 pitching seasons from 2002-2007, and looked at pitches per inning, pitches per game, innings per game, and innings per season to see if any of those metrics were linked to future injuries.
What they found was that there no significant correlation between how many innings someone pitched and likelihood of future injury. They also found that moderately increasing the number of innings each year had no effect on the risk of future injury.
"The point of our paper was to specifically to look at these cutoffs, these year-to-year changes in innings pitched," said Karakolis. "Our finding was that they didn't have any sort of correlation, it was all over the map."
The team looked at 10, 20, 30, 40 and 50-inning increases from previous years.
"A 10-inning increase and a 50-inning increase were both the same in terms of future injury likelihood," said Karakolis.
Each pitcher should have own limit
Instead, Karakolis said there should be individual biomechanical testing for pitchers to figure out how much stress their bodies can handle.
"Once you figure exactly out how much work you're putting on the tissues and then you can figure out how much work causes the tissues to become injured, you can use those measures now to actually control and limit the amount of pitches that a pitcher throws," he said.
'So you can have tailored individual limits for each pitcher, rather than having blanket limits like a 30-inning increase for all pitchers under 25 years of age," said Karakolis.
"I think that would be huge in terms of scouting and player development. I could figure out which pitchers are better suited to be a starting pitcher versus which pitcher is better suited to be a relief pitcher, a bullpen guy."
The idea of biomechanical testing is starting to take hold in the MLB this year. Tech company Motus Global pioneered a sleeve called mThrow that pitchers can wear that tracks motion and measures workload on a crucial pitching ligament, the ulnar collateral ligament, then relays that information through an app via Bluetooth.
Sports Illustrated reported the sleeve was spotted frequently during spring training, and could be approved for in-game use during the regular season.
Other teams are looking at data to help fight injury. The Los Angeles Dodgers and the Tampa Bay Rays have partnered with Irish company Kitman Labs to do data and biometric measurements to help spot injury risks before players get hurt.