EVERY PITCHER no matter his age, generates enough force on each pitch to rupture the ulnar collateral ligament in his elbow. It's a scary thought, for sure, but also an easy one to forget in the idyllic, emerald-grass setting that is Viera, Fla. Though Washington Nationals spring training has only just begun, a healthy crowd has turned out to watch fireballer Stephen Strasburg throw today's bullpen. It's been 18 months since the Nationals star underwent Tommy John surgery -- the reconstruction of that oh-so-delicate UCL -- at the age of 22; note the four-inch scar on the inside of his right elbow. Strasburg, who's known for touching 100 mph, doesn't disappoint. The fans, with their noses pressed through the chain-link fence, are thrilled. The Nationals, with their $15 million starter back on the mound after a year on the disabled list, couldn't be happier. He looks exactly the same as he did before his elbow blew up.

And therein lies the problem.



Thirty-seven baseball seasons have passed since orthopedic surgeon Frank Jobe performed the first UCL reconstruction on Dodgers southpaw Tommy John, whose name would become synonymous with the procedure. At the time, John was 31 years old with 124 wins and 11 seasons under his belt. He never threw heat like Strasburg, instead relying on a bottom-out sinker that forced ground balls. But the two pitchers -- as well as many others who have undergone UCL reconstruction -- have one thing in common: a mechanical flaw in the timing of their deliveries that causes the arm to lag behind the rest of the body, putting extra stress on the shoulder and elbow.

John wasn't told any of that in 1974, but he did learn the UCL connects the ulna in the forearm to the humerus in the upper arm and acts as the elbow's primary stabilizer. He also knew from fellow Dodger Sandy Koufax, who had retired in 1966 at age 30 after a short but brilliant career, that a damaged UCL meant you were done. What Jobe proposed to John sounded both crazy and simple: replacing his torn left UCL with a tendon graft from his right wrist. Though the physician gave him only a one-in-100 chance of returning to baseball, John liked the slim odds better than the idea of working at his buddy's car dealership back home in Terre Haute, Ind. So the surgeon sliced through the muscle on the inside of the pitcher's left elbow to expose his shredded UCL, drilled holes in the ulna and humerus and threaded the graft from John's opposite wrist through them in a figure-8 pattern. Then he sutured the remnants of John's original UCL to the graft for added strength, whispered a few words of encouragement and closed up.

Eighteen months later, John defied the odds and returned to baseball. Jobe's procedure soon proved so successful that it became the norm. Today, about 50 active major league pitchers have undergone Tommy John surgery -- around one in seven.

Despite the inevitable yearlong stint on the DL that rehab from the surgery requires, teams and pitchers seem to barely flinch at the diagnosis of a compromised UCL. "It's become an accepted side effect of the job," says George Paletta, the Cardinals' head team physician and orthopedic surgeon. That's because the surgery works; 92 percent of elite pitchers with reconstructed UCLs return to their prior level of competition for at least a year.

As miraculous as that sounds, it masks a loaded situation. To understand the epidemic of UCL injuries, The Mag interviewed dozens of biomechanics experts, pitching coaches, coaches for hire, pitchers and front office personnel. (Only a handful of major league pitching coaches accepted our interview requests.) The picture that emerges is of baseball at war with itself over the health of its arms. In one corner stands a cottage industry of scientists and biomechanics-promoting coaches who study motion for a living and have determined, through high-speed video analysis, that the sport's ignorance of arm-saving science is a shameful oversight. In the other is major league baseball, which, with rare and fleeting exceptions, clings to a deep-rooted tradition: If it ain't broke -- or can be fixed after a year on the DL -- don't fix it.

"The definition of insanity is doing the same thing over and over again and expecting different results."

-- multiple biomechanics experts interviewed for this story

Stephen Strasburg, drafted No. 1 in 2009, has yet to pitch a full season. Some biomechanical experts see his strained motion and worry he never will. Tom DiPace

To throw a baseball properly, a pitcher must get into the right position at the right time with the right succession of movements, like dominoes falling. Disruptions in this kinetic chain, as experts call it, cause problems at the weakest link, most often the elbow or shoulder.

Problems usually begin below the waist. The most telling moment in a pitcher's delivery, for instance, is the foot strike. When the foot makes contact with the mound, the pitching arm must be up and ready to throw. A righthanded pitcher should be showing the baseball to the shortstop, a lefty to the second baseman. (Among active hurlers, Cliff Lee is a good example.) But if a pitcher's elbows come higher than his wrists and shoulders, with the ball pointing down, he's demonstrating an "inverted W" -- a sign that his sequence is off and he's fighting his own body. Such poor timing leads to arm lag, evident when the throwing elbow trails the shoulder once the shoulders square to home plate. Strasburg exhibits both problems, forcing him and others like him to rely more on the arm's relatively small muscles instead of the more massive ones in the legs and torso. Throw after throw, the shoulder and elbow are under extra stress. The higher the pitch's velocity and the worse the flaw, the more the arm suffers. And the more a pitcher throws, the worse it gets.

Arm lag and improper sequencing were likely to blame for Strasburg's UCL tear, as well as for those of almost everyone else knocked out by the injury. "The timing is subtle," says the American Sports Medicine Institute's Glenn Fleisig, who has analyzed more than 2,000 pitchers and is one of the world's foremost authorities on pitching biomechanics. "It's the difference between good and great and healthy and injury-waiting-to-happen."

Strasburg was probably in trouble from the get-go. He didn't rupture his UCL on one pitch with the Nationals -- even if a pitcher feels a pop on a particular pitch, his UCL was anything but pristine before the incident. Like a rope, Strasburg's UCL probably started to fray the moment he began pitching off a mound, the extra height of which can compound the stress of each pitch. It likely got worse not only because of his mechanics. Kids who throw the hardest pitch the most: They get hitters out. Famed orthopedic surgeon James Andrews, who founded ASMI in 1987, says he has seen a five- to sevenfold increase in high schoolers requiring UCL reconstruction since 2000.

"The No. 1 risk factor for UCL injuries is poor mechanics," he says. "The No. 2 factor is overuse. And if you overuse with poor mechanics, you're doomed."



God-given genetic superiority and freakish athletic ability often help those with less-than-ideal pitching mechanics make it to the majors, which is why you will find shockingly few exemplars of pitching mechanics on Sunday Night Baseball. "Everyone knows smoking is bad for you, yet people still smoke," says Yankees pitching coach Larry Rothschild. "It's the same with pitching. I've seen guys who don't have great mechanics pitch for a long time. The body adjusts."

Until it doesn't.

"You have to be open-minded. Closed minds don't make progress."

-- Rangers president Nolan Ryan

Regular-season days MLB pitchers recovering from Tommy John surgery have collectively spent on the DL in the past five years. MLB teams have spent $193,503,317 on their salaries during their recoveries. ESPN The Magazine

To anybody involved with the biomechanical analysis of pitching, it's difficult to imagine a world without it. To anybody even half interested in baseball, it's also difficult to understand why it's not more accepted at the sport's highest levels.

For more than a hundred years, pitching mechanics have been evaluated at 32 frames per second -- the best the human eye provides. A pitcher's delivery, from first movement to ball release, can take as little as 1.4 seconds. In that tiny window, coaches, scouts and fathers try to assess dozens of variables, such as "hip and shoulder separation" and "pitching arm external and internal rotation." It's a tall order, if not an impossible one. "What the eyes see and what actually takes place are two different things," says Tom House, a former big-leaguer-turned-pitching-coach who now heads the Rod Dedeaux Research and Baseball Institute at the University of Southern California. "You see reality when you see what happens at 1,000 frames per second. It's a humbling experience."

The baseball community that makes a living off analyzing that reality is a quirky lot. Some are mechanical or biomedical engineers, like Fleisig. Some are retired pro pitchers, like House and Cy Young winner Mike Marshall, who has a Ph.D. in exercise physiology. Some are kinesiologists. Some are even self-taught, like coach-for-hire Alan Jaeger, who helps clients "merge the mechanics of the Western athlete with the insight of the Far Eastern mind." Their approaches vary, but they all believe that by addressing a pitcher's biomechanics and physics, they can improve performance and decrease injury. Not that they always agree. For example, Marshall advocates an ultrahigh arm slot. Jaeger is an advocate of long toss to build arm strength and stretches pitchers out as far as 380 feet. They find each other's untraditional approaches controversial and often fail to present a completely united front. While the small particulars they disagree on nearly bring them to fisticuffs, all agree that any flaw that disrupts the timing of a pitcher's kinematic sequence is problematic.

Collectively, their research can be as persuasive as it is cutting edge. A total of 2,000 pitchers -- including six future Cy Young winners -- have visited Andrews and Fleisig at ASMI's lab. Using a camera-and-computer system that three-dimensionally tracks data from reflective markers affixed to a pitcher's body as he throws, ASMI takes 41 measurements; think of it as an MRI of the pitching delivery. Afterward, Fleisig compiles a detailed report called a Biomechanics Evaluation about the pitcher that diagnoses problems with annotated video stills and recommends solutions. "When pitchers are young, they're receptive and willing to fix problem areas," says Reds minor league pitching coordinator Mark Riggins, who made several trips to ASMI while working with the Cubs. Crucially, the packet compares the pitcher to the exemplars in ASMI's database who threw the hardest without injury.

And yet despite the stature of Andrews and Fleisig, only about one-tenth of ASMI's clients played pro ball at any level. When pros do visit, they often find the screening advantageous. Braves pitcher Tim Hudson spent the early part of his career in Oakland, where pitching coach Rick Peterson, a biomechanics guru, took him to ASMI for mapping. "I think it's a great test," says Hudson. "You can do it when you're pitching really well, and then, if you struggle or have pain" -- Hudson himself later had Tommy John surgery, from overuse -- "do it again. Instead of trying to eyeball it with regular video, you can actually use the science to compare the two." Fleisig also recalls CC Sabathia and Cliff Lee visiting in the early 2000s as promising young Cleveland Indians; he's mum on the details, but they soon became two of baseball's most dominant pitchers.

Such an analysis reveals, for example, an issue late in the delivery -- such as a tilted head position -- that biomechanics-minded coaches address much earlier in the pitching motion, just as an engineer would need to right a listing skyscraper at its foundation rather than at the 15th floor. The pitching coach also creates a full program of mechanical drills tailored to correct nearly all woes, even a habit like arm lag. "With an approach that includes strength training and mechanics, there's not much you can't fix," says independent pitching coach and former scout Paul Reddick.