Inside his office, above the oversized, high-definition monitor where he shows injured baseball players images of their damaged elbow ligaments, Dr. Naotaka Mamizuka hung a row of photographs. Most were him posing with patients, famous athletes in Japan, celebrities, the sorts who would elicit an ooh or an aah from the everyday people he saw. One person in particular stood out to his clientele.

“That’s Ohtani,” Mamizuka said. “Do you know him?”

I did. Everybody in the baseball world knew Shohei Ohtani. It was August 2014, and I was in Mito, a two-hour train ride from Tokyo up the east coast of Japan, where Mamizuka practiced. He spent most of his time performing spinal surgeries. Twice a week, for four hours a day, baseball players would flood his office – up to two dozen a day, if he could cram them into his schedule, and occasionally fewer, if someone important was coming to visit.

Shohei Ohtani qualified as important. He was 20 years old, in the midst of his first full season with the Hokkaido Nippon Ham Fighters, and was the future of Japanese baseball. His fastball regularly clocked in at 100 mph, sometimes faster, harder than any Japanese pitcher ever had thrown. He could also hit, with rare power in a league that produces scant sluggers. He had seen Mamizuka to get a sense of his arm’s health. All was well.

This heartened Mamizuka. It also scared him. He had seen thousands of elbow MRIs, turning a curiosity in baseball medicine into an expertise perhaps unmatched in Japan. That day he examined 20 children, ages 9 to 17. He diagnosed injuries in 19 of them. Japanese baseball, a year-round pursuit in which the best teams practice 360 days a year, taking a short break only at Christmastime, runs through elbow ligaments with the efficiency of a plow through dirt. That Ohtani escaped without severe damage to his ulnar collateral ligament, the triangular band of tissue that holds together the upper and lower bones of the arm and allows man to throw a baseball, felt to Mamizuka something of a miracle. Like, maybe this athlete blessed with the ability to throw like few others and hit with great force happens to be the outlier with regard to injury, too.

View photos Angels starter Shohei Ohtani watches a pitch during the third inning of his game against the Royals (AP). More

But then he considered all he knew about the elbow, about Ohtani, about the intersection of this fallible piece of tissue with this capacity to throw a ball at amazing speeds, and he harkened back to something he said earlier in the day, when he was imploring a 16-year-old with arm pain not to throw with maximum effort.

“Power is bad,” Mamizuka said. “Power is bad.”

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Nobody knows for certain what causes UCLs to break. It is some combination of usage, movement, velocity and genetics, and it differs in every player. Players in Japan, and in travel-ball-heavy areas of the United States, suffer because ignorant – or, quite often, selfish – coaches abuse their arms with impunity. Others’ movement patterns – mechanics, as they’re most often deemed – cause excessive stress and strain and lead to a fraying or acute tearing of the ligament. The speed of one’s fastball correlates strongly with UCL damage, though it’s not as simple as throw hard, get hurt. DNA’s role remains a mystery, but doctors and researchers agree that some players are simply born damned and others hearty enough to withstand extremes in other areas.

Exactly what caused Shohei Ohtani’s UCL to break doesn’t matter so much as the fact that it’s broken. The Los Angeles Angels announced Friday that two months into Ohtani’s career in Major League Baseball, he has a grade-2 sprain of the UCL – a partial tear significant enough to warrant Tommy John surgery in thousands of others, from junior high to the major leagues, who have received the same diagnosis. The Angels knew this was a possibility, knew that he had undergone a platelet-rich plasma shot in his elbow in October after being diagnosed with a first-degree sprain, knew that the combination of Japanese usage, his dynamic fastball and a previous injury made him especially susceptible to more.

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