Free The Arm by Jeff Passan Page A

its future.
    Following a lockout of the players during spring training in 1976, John reported to Dodgers camp, ready to rejoin the rotation. He was turning thirty-three in May. Only eight pitchers in baseball were older than thirty-four, the eldest of whom was spitballer Gaylord Perry, at thirty-seven. Even if the surgery proved successful, John figured he had only a few good years left.
    Tommy John returned to the major leagues on April 16, 1976, for the 319th start of his career. He never missed another. There would be 382 postsurgery starts in all, more than twice as many as anyone who underwent UCL replacement at the age of thirty-one or older since. John threw nearly three hundred more innings with his new UCL than he did with his original. He retired at forty-six with 288 wins, the seventh-highest total among left-handers in major league history, a career ERA of 3.34, and almost five thousand innings pitched. He was a walking billboard for the power of medical innovation, the genius of Frank Jobe.
    More than forty years later, the original Tommy John surgery remains the best. It saved the arm from what was millions of years in the making.

CHAPTER 4
Chimps, Quacks, and Freaks
    A ROUND TWO MILLION YEARS AGO, long after they had split off from their chimpanzee ancestors and benefited from bipedalism, developed brains, lengthened legs, and expanded waists, the species that eventually evolved into human beings underwent a lesser-known adaptation involving the shoulder. The shrugged posture of earlier primates disappeared and grew to resemble our shoulders of today, with the glenoid cavity—the socket of the shoulder’s ball-and-socket joint—no longer angled upward but pointed out and into the humeral head.
    The slight difference changed humanity—and would eventually make Tommy John surgery necessary. No longer was Homo erectus bound by the physiological limitations of chimpanzees. Sandy Koufax himself couldn’t teach a chimp to throw a ball much more than 20 miles per hour. Slightly lowering the junction of the shoulder in early humans opened up their range-of-motion treasure chest. The new shoulder allowed H. erectus to throw spears, rocks, and other hunting implements, which allowed them to expand beyond the vegetarian diet of their forebears, which facilitated moves across desert landscapes where no plants grew, which led to the dispersal of people worldwide. All because humans can throw things.
    To understand the arm, I needed to understand its origins and what it went through to get where it is today. So I called Dr. Neil Roach, a biological anthropologist who specializes in human evolution. Roach had just published a paper in which he studied college-aged pitchers and tied modern man’s superior throwing ability to the new body of H. erectus storing elastic energy in the muscles, tendons, and ligaments of the shoulder.
    Today’s shoulder can flex straight in front and extend directly back. It flares out to the side and moves up (abduction) or down (adduction). No movement in the entire human body can match its maximum speed at internal rotation. And this was the missing link Roach could explain: not how we got from Koufax to today but how we grew into overhand-throwing marvels in the first place.
    â€œWe had a hypothesis that elastic energy was being used for improved performance,” Roach said. “I was surprised at how effective this mechanism could be. These are tiny little ligaments and tendons, and yet they’re accounting for more than fifty percent of the energy used for these rapid motions.”
    While the expansion of the waist and similar vital changes occurred in other species, H. erectus first reaped the benefits of the shoulder’s emergence about two million years ago, presumably ushering in the hunter-gatherer form of society. The first throwers were pragmatists. They just wanted to eat. The blather about throwing being an unnatural motion could not be further