Just three years ago the Blue Jays were among the most cautious teams in Major League Baseball in terms of how they handled their young pitchers. Minor-league prospects were developed delicately: held to strict pitch and inning limits, and graduated slowly through the system with their innings carefully increased by 20 per cent each year.

The organization was occasionally criticized for “babying” its prized young arms, but it was merely following the prevailing wisdom of the industry, which was trying to stem an epidemic tide of pitcher injuries. In the big leagues, star hurlers such as Stephen Strasburg were even being shut down before the playoffs in an attempt to protect their fragile elbows and shoulders.

Teams knew there was no silver bullet, but the best evidence suggested that reducing workloads offered the best chance at protection.

But the injuries never abated — pitchers continue to be as vulnerable as ever — and last season the Jays dramatically changed course, essentially throwing innings limits out the window and fast-tracking any prospects who looked ready. The team still monitored pitchers on an individual basis and adjusted workloads on a case-by-case basis — you saw it last season when Drew Hutchison was occasionally given extra rest in his first season following Tommy John surgery — but gone were the definitive caps.

This year, their opening-day roster contained four rookie pitchers, including 20-year-old relievers Roberto Osuna and Miguel Castro — neither of whom had thrown a pitch above A-ball — and 21-year-old Daniel Norris, who rose four levels of the Jays’ system in a matter of months last year.

Now, a new study by the University of Waterloo, published in April’s Journal of Sports Medicine and Physical Fitness, supports the Jays’ abrupt about-face. The study, which looked at every major-league pitcher under 25 who made at least one out between 2002 and 2007, found no correlation between innings pitched and future injury. No link either for number of pitches thrown. The practice of increasing innings by 20 per cent was found to offer no more or less protection.

“We didn’t find any correlation between those so-called workload metrics and future injury risk,” said Thomas Karakolis, the lead investigator, who is also a visiting fellow at the Department of National Defence.

The study looked at more than 761 pitcher seasons and also examined each pitcher’s minor-league workload in Double-A and Triple-A. All pitcher injuries through the 2008 season were considered.

Restricting workload is “definitely necessary,” Karakolis said, because pitcher injuries are most often caused by overuse. Ligaments and tendons fail under a cumulative load and can no longer bear the stress of throwing a baseball. But simply counting innings and pitches “is not a sensitive enough measure,” he said, pitchers’ bodies are not created equal and neither are the pitches they throw.

Some may fatigue after 50 pitches, while others can throw 130. Similarly, the stress borne by a pitcher’s elbow ligament by 50 changeups is different from throwing 50 sliders.

“By just putting blanket innings limits on pitchers or pitch counts, that’s not going to get you the results you’re looking for in terms of reducing the number of injuries.”

Blunt measures such as pitch counts make sense in Little League, where coaches are often volunteers and lack specialized training, Karakolis said. But in the big leagues, where teams should have the resources to access better tools and obtain richer data, there’s no excuse not to use better information.

Karakolis said the “golden ticket” in gauging injury risk is biomechanical analysis, which has been embraced by some MLB teams to varying degrees. One of the biomechanics tools currently available is the so-called “Tommy John sleeve,” which is a fitted sleeve embedded with sensors that is worn by the pitcher and can transmit data on how much stress is being put on the elbow with each pitch and whether or not the pitcher is growing fatigued.