In the first segment of this series, we examined the surge of injuries to the ulnar collateral ligament (UCL) in baseball pitchers’s elbows. Today, we dig into its causes. Many of these injuries happen to pitchers well before they reach the major leagues and are often the product of factors that begin when the player is in Little League.

Youth Sports Environment

Injury rates among young athletes are soaring and not just in baseball. Knee, back and shoulder injuries in softball; ACL (knee ligament) injuries in basketball and soccer and shoulder injuries for swimmers are a few examples. And, of course, there’s the epidemic of ulnar collateral ligament tears in baseball players.

The blame for the explosion of injuries lies in large part on today’s youth sports environment. Year-round schedules, single-sport focus and an emphasis on performance over fun have led to seasons without end, emotional and physical burnout, and overuse injuries.

“Fifty percent of injuries in pediatric sports medicine are due to overuse, which are highly preventable,” said Dr. Joel Brenner, chair of the Council on Sports Medicine and Fitness.

Youth sports — baseball, softball, basketball and soccer are examples — in the U.S. are suffering significant declines in participation as kids increasingly focus on one sport at an early age. In contrast, elite travel teams are flourishing, with reports showing them more than doubling in numbers in the past 10 years.


Strong incentives drive this choice. The ultimate goal is more playing time in high school, maybe a college scholarship and, in a few cases, professional contracts. Parents, often encouraged by travel and club team coaches, fear their kids will be left behind if they don’t specialize early, even though the research and coaches at the college and professional level say otherwise.

When young people only play one sport, they overuse certain parts of the body. Young pitchers now throw all year; they play on elite travel teams; and they attend showcases where they are rewarded for throwing the ball through the backstop.

Dr. James Andrews, one of the leading Tommy John surgeons in the country, points to year-round baseball as the biggest risk factor. “These kids are not just throwing year-round, they’re competing year-round and they don’t have any time for recovery. And of course the showcases where they are pitching for scouts, they try to overpitch and get hurt.”

Seduction by Velocity

We know why pitch speed has become the holy grail of pitching — it works. The reason couldn’t be simpler. The faster the ball is thrown, other factors equal, the less time the batter has to react.

The sport of baseball has been re-organized beginning-to-end to produce pitchers who throw harder. Better training regimes make players more fit. New, sophisticated throwing programs have been developed to produce stronger arms. Countless websites offer kids advice on how to increase their pitch speed. Radar guns, all the way down to Little League, reinforce and enable the obsession. We worship at the altar of their readings. Recruiters fixate over every mile per hour. And then there’s the surgical procedure that fully restores an elbow with a torn ligament.

MPH readings generate oohs and ahhs that befit a love affair, which is exactly what the sport of baseball is having with power arms. Why did your favorite team acquire that new pitcher? “He has a (hushed voice) power arm.” End of explanation. New meanings have been created for a set of verbs to describe pitch speed. He sits at 94-96. He touches 100. Ooh, ah, velocity.

The investment of time and resources into developing pitch speed has paid off. The average fastball velocity has risen steadily in the major leagues, with pitchers in 2015 topping 92 mph for the first time.


Success — another mighty incentive — reinforces that trend at the highest level. The hardest throwing major league teams make up a disproportionate share of postseason berths and have the most regular-season wins. This year, the five teams with the best records (and seven of the top nine) are in the top third in average velocity.

It won’t come as a surprise that research shows the harder a pitcher throws the more likely he is to suffer a UCL injury. Jon Roegele from Baseball Prospectus (2012) found “after controlling for pitching role and age, pitchers headed for Tommy John surgery all threw pitch types harder, and more fastballs and sliders than average.” A study (2010) by orthopedic surgeon Dr. Brandon Bushnell concluded “pitchers throwing at a higher maximum velocity had higher risk of elbow injury” and those “at the highest velocity had injuries requiring surgical reconstruction.”

Shouldering the Load

Another major factor in the rise of UCL injuries appears to be that the elbow is, pardon the expression, shouldering more of the pitching load. When a pitcher throws a baseball, energy travels through the body and is then released with violence by the arm. Think of the forearm hurtling forward. The weakest part of the arm is least equipped to bear the brunt of the force and tends to be injured. For years, the pitcher’s shoulder absorbed the majority of the abuse.

But new strength and conditioning programs for the shoulder have dramatically cut rotator cuff and other shoulder injuries. Success at protecting shoulder health has had the perverse effect of increasing elbow injuries. The strengthened shoulder passes the force of the pitching motion down the arm, where the 2-inch UCL hangs on for its life. With pitchers today in better physical condition — and throwing harder than ever before — the weak link has become the elbow ligament, the part of the arm that can’t be strengthened by working out or training.


Jeff Zimmerman, The Hardball Times

Disabled list numbers show the dramatic transfer of injuries from the shoulder to the elbow. From 2008 to 2014, disabled days lost to shoulder injuries fell from 7,000 to 3,000 — a reduction by more than half in just seven seasons. That’s a huge and welcome success from the standpoint of taking care of the shoulder. But at the same time, days lost to UCL injury jumped from 5,000 to 8,000. [In the graph above, the blue line shows the trend in days lost due to elbow injuries. The red line measures shoulder injuries.] The connection between fewer shoulder injuries and more elbow injuries is a simple straight line down the humerus.

Risk-Taking Behavior

The final risk factor for UCL injury comes with a heavy dose of irony.

The economic theory of moral hazard occurs when a person or party gets involved in a risky event because they know they are protected against the risk. New protections, under certain circumstances, can actually encourage risk-taking behavior. The classic example in economics textbooks is when people move into flood-prone areas after receiving flood insurance.

A moral hazard operates in the area of UCL injuries. In the past, when elbow injuries meant the end of careers, players had an incentive to be more careful with their arms. Today, the success and recovery rate of Tommy John surgery enables risk-taking on the elbow. The surgery — a form of insurance against the loss of career — is encouraging behaviors that cause the procedure to be needed in the first place. Young pitchers view injury risk as “getting their elbow surgery out of the way.”

Moral hazard operates at the major league level as well. Pitch counts, limits on innings pitched and bullpen specialization, policies designed to protect arms through workload regulation, actually compound the risk done by high velocity. Shorter appearances green light pitchers to throw as hard as they can. Relievers, who throw for one inning or less, are more likely than starters to damage their UCLs.


As with many social ills, the epidemic of Tommy John surgeries has a number of mutually reinforcing causes. Stan Conte, the Los Angeles Dodgers’ Vice President of Medical Services says rising UCL injury numbers are due to “pitch counts, fatigue, velocity, youth baseball — all those things.”

There’s no paradox of irresistible force meeting immovable object here. In this case, the combination of powerful forces – the allure of scholarships, pro contracts, wins and workout regimens – devastates the quite movable ulnar collateral ligament. Broken young elbows and overflowing operating rooms are the inevitable end result.

In part three of this series, we’ll take a look at the surgical procedure that revolutionized outcomes for those with torn UCLs And we’ll learn about the two men – doctor and patient – who were responsible for that paradigm-shifting development, despite the contrary plans of Adolph Rupp and Adolf Hitler.