Are pitchers’ severe elbow sprains rarer in Japan than in MLB? If so, what is the principle issue, how might context lead to different outcomes on different sides of the Pacific, and what do these say about the future of these injuries in Japan, especially for those pitchers here who throw really hard?
Could it be that Japan is doing something right that MLB might learn from? These questions were posed recently by my podcast partner, John E. Gibson (@JBWPodcast).
One of the advantages of being independent of MLB is that Japan does things differently for different reasons. Thirty years ago, Japan was different in that complete games were still expected from every regular starting pitcher, and it was not uncommon to see a really good pitcher in a high run context throw 140 to 150 pitches three times over a 15-day span until his career was essentially over at the age of 30.
Japan is no longer an outlier in that department, but it is an outlier with a fairly fossilized six days between starts, with the starting pitcher showing up to practice the following day to make sure everything is intact, and then taking the next day off.
Travis Sawchik recently published a superb article in The Score, titled, “Velo vs. Injury: Is there a better way for pitchers?“
Sawchick found minimum velocities in MLB are rising faster than maximum velocities, suggesting more maximum-effort pitches. He also stated that 37 percent of the pitchers on active MLB rosters have had Tommy John surgery.
I actually do have the material on hand in the form of html files needed to learn whether a similar phenomenon is happening in Japan, but need to write some code to capture it, so I’ll pass on that for a moment and simply make some obvious points.
- Severe elbow sprains that call for surgery are indeed rarer in Japan. I checked every active pitcher the first week of this season to see if he had a published record of surgery to repair an elbow ligament sprain.
- Dr. James Andrews, who has just retired from a career that included repairing elbow sprains, said recently that the current epidemic in America is not limited to professional pitchers, and that most of the surgeries performed, either Tommy John or his cousin “the brace,” are on high school and college pitchers.
- Dr. Kozo Furushima, who has performed a huge number of Tommy John surgeries in Japan, said surgeries on Japanese college pitchers are also increasing rapidly.
Japan’s TJ frequency
I went through the active pitchers for the first week of this season, and counted 143 pitchers who were whose pro careers essentially started in Japan – this includes SoftBank’s Livan Moinelo, since his pro experience in Cuba was extremely limited before playing in NPB and his teammate, Carter Stewart Jr., who turned pro here.
Of these, 12 have published reports Tommy John surgery. Four of the 57 starting pitchers have undergone TJs, and four of the 86 relievers. Overall, the percentage in Japan is 8.4 percent, but it’s 14 percent for starters and 4.7 percent for relievers. Two of the starters had their procedures done while they were still in university. On top of that, three former university pitchers had Tommy Johns this spring, two before they ever pitched in an official game.
This supports the idea that the problem is at least as bad in Japanese universities as it is in the pros.
Is the pitch timer to blame?
The Major League Baseball Players Association recently blamed the pitch timer on the rash of injuries, but that seems silly, as there has been a steady increase over the last decade or so.
Bill James studied how common it was for pitchers to retain their value and concluded:
“The rates of pitcher value retention have decreased steadily in recent decades, and have declined sharply in the last few years. This is fully consistent with the wide-spread belief that pitcher injuries are increasing.”
The point being that it is far more common now for a pitcher of a certain established quality to suddenly lose value than it used to be.
While pitch timer introduced in 2023 may have contributed to some injuries, blaming an epidemic that has been going on for years seems disingenuous.
My take
The elbow sprain epidemic tracks with two advancements and a subsequent strategic change:
- the realization through research that any given pitcher is more effective working out of the bullpen than as a starter, and
- advances in the ability to monitor physical motion and the movement of objects through sensors, radar and high-speed video that enabled pitchers to maximize speed and spin, and
- a decision by teams that the risks of maximum effort to produce speed and spin could be reduced by limiting pitch counts.
Dr. Andrews suggested that the problem with increasing the ability of young pitchers to throw harder is the culprit.
“We’ve learned in our research lab that baseball is a developmental sport. The Tommy John ligament matures at about age 26. In high school, the red line where the forces go beyond the tensile properties of the ligament is about 80 mph.”
– Dr. James Andrews
While MLB and NPB are not the direct cause of high school and college pitching injuries, they are driving the bus through their increased focus on velocity and spin.
Young pitchers who aspire to be the best in the world know that if they have the resources to access high-tech training facilities, they can get an arm up on others vying for the limited number of opportunities to play pro ball.
The knowledge of how to throw harder younger is now being shared with Japanese pitchers, and the average fastball velocity is ticking up every year in both the Central and Pacific leagues.
The Japan difference
Although Dr. Andrews said the number of surgeries performed on youth baseball pitchers has sky rocketed, Dr. Furushima said Japan is moving in the other direction, and while that’s a good thing, it’s not really a solution.
If increased velocity is turning school-age pitchers into Tommy John candidates in America, Japan’s issue has historically been far worse, not because of technology or a focus on velocity but because of extreme overuse and a lack of rest because of the way youth baseball is structured here.
Elementary school-aged players who are good at pitching have traditionally been exposed to tremendous overuse because amateur competition, with the exception of college ball, takes place in single-elimination tournaments.
Teams practice as much as 10 times as often as they play, so when they get into tournaments, they tend to go all out to win every game, and use their best pitchers over and over and over.
Overuse in young arms in which the growing bones are still soft leads to a kind of fracture where the bone is pulled apart by the ligament. The overuse that leads to these elbow, shoulder and knee injuries would be mitigated if players have a few months each year when they are not throwing baseballs, but because of the way sports are organized as year-round school activities, “months of rest” is an alien concept here.
Here’s what Dr. Furushima had to say about the situation in Japan:
“In Japan, for several years now, we’ve been conducting screenings from a young age and providing training for coaches, as well as introducing pitch count limits, to address baseball injuries. As a result, the incidence of Tommy John surgery during youth has decreased.”
“Currently, it’s college students who are most frequently affected. However, the numbers are lower than they were a decade ago in Japan. I believe that the incidence in NPB (Nippon Professional Baseball) has significantly reduced compared to before.”
Indeed, 10 years ago there were at least two active NPB pitchers with multiple Tommy John procedures, Yakult’s Shohei Tateyama had three and Chunichi ace Kazuki Yoshimi had two. Currently, there are none.
If Dr. Furushima is correct about the increasing scarcity of elbow injuries in NPB that is probably due to decreasing pitch counts, we may be soon be facing the same trouble MLB is now dealing with as velocities here follow suit.
Of course, we can’t talk about velocity in Japan without referencing the country’s fastest and most promising pitcher, Roki Sasaki.
So what about Roki?
Since he was in high school, the public knew two things about Roki Sasaki’s metrics: He could throw a baseball harder than nearly anyone in Japan, and his bone density that was significantly lower than other players his age.
Sasaki’s current manager, Masato Yoshii, who oversaw his development as a teenager in his duty as the Lotte Marines’ pitching coordinator, has confirmed that Sasaki did not pitch at all as a first-year pro was due primarily to the inability of his body to bounce back from the inflammation caused by throwing.
After that comment, Yoshii added a twist I did not quite know what to make of at the time.
“It’s not just Roki,” Yoshii said in March. “We need to be careful about a lot of young players coming out of high school getting too strong, because it leads to injury.”
Yoshii has a masters degree in physical education with a focus on coaching, and said his course work required him to do research and be familiar with others’ research, but I didn’t necessarily think Yoshii was specifically talking about pitchers.
On April 7, Sasaki said, “I wasn’t able to throw as hard I normally can, so I wasn’t fatigued.”
Perhaps it was just me, but noticing Sasaki hadn’t even been touching 160 kph, (99.4 mph), a figure he used to surpass often, especially early in the season, and the infrequency of his preseason appearances, made me think there was a physical issue preventing him from throwing the ball harder.
These days, pitchers generally throw the ball as hard as they can and still command it, and if that was what Sasaki was doing, his not being able to reach his accustomed velocity would not make him less fatigued.
But then I saw Dr. Andrews’ quote about speed and the fragility of immature ligaments, and added that to Yoshii’s comments about how too much muscle on players coming out of high school could lead to injury, and it clicked.
It seems to me now that Sasaki was not saying he was physically unable to throw the ball harder. It seems more likely that he was saying he was under orders not to throw the ball anywhere near as hard as he can, and thus was less fatigued than normal. Our boy has been ordered to pitch at cruising speed to lessen his injury risk.
