Dr. Chuck Thigpen on Arm Health in the Age of the Pitch Clock

The human arm is a magical instrument. Under the right circumstances, it has all the necessary components to hurl 100-mph fastballs and mind-bending curves. That shouldn’t be possible. Anyone who has watched a major league pitcher throwing in slow motion knows exactly what I mean.

Dr. Chuck Thigpen developed his passion for this extraordinary appendage during his time at the University of North Carolina, where he completed his PhD in Human Movement Science. UNC just so happens to be the alma mater of pitchers like Zac Gallen and Daniel Bard, and fittingly, it’s also where Dr. Thigpen discovered his fondness for baseball, a fondness that has only grown throughout his career as an athletic trainer and clinical research scientist. He currently works as the Head of Clinical Excellence for ATI Physical Therapy.

When I spoke with him last Friday, Dr. Thigpen expressed his agreement that pitching practically defies the laws of physics. In his expert opinion, it’s hard to believe the arm doesn’t just “fall right off” considering what a pitcher has to do. Perhaps he was exaggerating the slightest bit with that assessment, but the point still stands. After all, some of his latest research (alongside Dr. Ellen Shanley) has focused on identifying risk factors for arm injury in pitchers and preventing recurrent injuries. He knows better than almost anyone how difficult and dangerous professional pitching can be.

“It’s not if you’ve had an arm injury,” he explains. “It’s just ‘how many?’ and ‘when was the last one?'”

As you might imagine, given his field of study, I was curious to speak with Dr. Thigpen about the potential adverse effects of the newly implemented pitch clock. There has been no shortage of speculation in the baseball community about the harm the new rules could cause. Max Scherzer famously voiced his concerns about the clock last summer, wondering if it could lead to an increase in injuries. Dr. Thigpen is similarly concerned.

“How is it going to affect arm recovery, and how is it going to affect injury? Our suspicion,” he says, “is it’s going to have an impact.”

Even the experts are speculating at this point; we simply don’t have the data to draw a formal link between the pitch clock and an increase in arm injuries. Even so, Dr. Thigpen believes there is legitimate reason for concern.

The human body doesn’t always react well to change, especially when working at such a high level of exertion. The upper extremities, in particular, are quite sensitive to the unexpected. As an example, Dr. Thigpen points to the increase in arm injuries during and following the COVID-shortened season. Major leaguers weren’t prepared for the rigors of a jam-packed 60-game schedule. Minor leaguers weren’t prepared for the consequences of sitting out for a year. The result was brutal.

While players had more time to prepare for the pitch clock than a global pandemic, the new rules still represent a massive change in how the game is played. It stands to reason that such a change could lead to injuries.

Dr. Thigpen also cited some research that found relief pitchers have a higher rate of injury than starters. Relievers are at a higher risk, he theorizes, because they pitch more frequently with less rest between outings and they often enter games in high-leverage situations. Downtime is essential for recovery, and high-leverage work puts added stress on the body. Less downtime plus more stress is a recipe for disaster.

Perhaps you can see where this is going. The pitch clock gives pitchers less time to rest between pitches. It also speeds up the game overall, giving them less time off between innings. Moreover, the pitch clock creates artificial high-leverage situations, according to Dr. Thigpen. He thinks it can make more mundane spots feel like “the bottom of the ninth with two outs and a man on second and third.” Every pitch becomes a race against the clock. Thus, the pitch clock makes every outing seem more like a relief outing; it produces conditions that can make a pitcher more susceptible to injury.

With this in mind, another question pops up: are relievers at an even higher risk for injury this season? Will the compound stressors of regular relief pitching and the new rules combine to make especially perilous conditions? Unfortunately, Dr. Thigpen thinks the answer is yes. He is particularly worried about middle relievers, those who regularly pitch on back-to-back days, because he thinks the lack of rest they receive will have a cumulative effect. Starters, on the other hand, may have the least to worry about, presuming they still get their regular four to five days of rest between starts.

So how can pitchers stay safe this season and beyond? Dr. Thigpen is a big proponent of the three P’s: preparation, preparation, and preparation. In general, he believes preparation is the best way to avoid injury. In this case, he thinks pitchers could have better prepared by practicing with a simulated pitch clock during the offseason.

“I think pitchers can adapt to [the pitch clock],” he says. “But I’m relatively certain that pitchers didn’t change how they prepared for the season.” As evidence, he brings up the myriad pitch clock violations that occurred early in spring training.

Dr. Thigpen doubled down on this theory when I asked if the bigger problem was simply the shift in routine or the fact that 15 to 20 seconds isn’t enough time between pitches. He acknowledged that more rest time generally promotes good health, but a lack of preparation is his primary concern.

“We need to match preparation to how we’re actually asking athletes to perform.”

Human beings can handle a shocking amount of physical stress, but we need to know how to recover. Injuries often occur when our bodies aren’t prepared to recuperate from the rigors we put them through. In other words, the stress of working under the pitch clock isn’t so much the problem. The problem is how pitchers recover in between outings. As Dr. Thigpen explains, “You’ve got to train your body to adapt to whatever stress you’re going to put it under.”

Preparing for the pitch clock is easier said than done, of course. It’s one thing to practice pitching with a timer, but it’s almost impossible to simulate the high-stress environment of a professional baseball game. Thus, if any pitchers or teams managed to find a way to successfully imitate high-leverage situations with the pitch clock during offseason workouts, they might find themselves with a sizeable advantage this year.

My final question for Dr. Thigpen was a bit of a curveball, so to speak. Was there any chance, I wondered, that the new rules could actually lead to fewer occurrences of certain injuries? While players have less time to recover between pitches, the games are also significantly shorter, so players are on their feet for less time each day. I thought this might help starting pitchers, who are used to long, laborious outings, and catchers, who could benefit from less time spent crouching low to the ground.

My guest took a moment with this one. He was careful not to answer any of my questions too definitively, always making it clear that his responses were only suppositions. Ultimately, he answered my question with a question of his own.

“The question on the table for us to understand,” he began, “Is has the shortened time just made things more intense? Am I running a mile in six minutes instead of eight? Or, by shortening the games, are we limiting exposure overall?”

He was doubtful that shorter game times would reduce arm injuries, specifically for pitchers, because the pitch clock just makes pitching more intense – like turning an eight-minute mile into a six-minute mile. A mile is still a mile, and moving faster only makes the challenge harder.

On the other hand, he was willing to entertain the possibility that we could see fewer injuries to the lower extremities. As an example, he suggested hamstring strains – the most frequent ailment among baseball players – could become less common. However, this wasn’t a formal prediction. We don’t have the necessary data to make a well-supported argument about the effect that shorter games will have on the hamstring.

I’ve said it several times before, but it bears repeating once again: we won’t know the consequences of the new rules until all the games have been played. Even then, we’ll have to wait for more research to be conducted before we can know for sure if the pitch clock led to an increase in arm injuries (or a decrease in hamstring strains). Still, the impact of the pitch clock will be one of the central storylines to watch this season, and the effect it has on pitcher health is something to note as the year goes on. Dr. Thigpen summed it up well, so I’ll let him bring things to a close.

“Here we are. We’ll see what happens.”

About Dr. Chuck Thigpen: Dr. Thigpen, PhD, PT, ATC, is a Clinical Research Scientist for ATI and Director of Observational Clinical Research in Ortho­paedics with the Center for Rehabilitation and Reconstruction Sciences.