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How to Survive Baseball’s ‘Most Fearsome Injury’

Mark Prior
Former MLB Pitcher Mark Prior Credit: Wikimedia Commons

As a 15-year-old high school pitcher, my fastball hissed into the catcher’s mitt at 80 on the radar gun. By the end of my sophomore season, the pitch was 10 miles per hour slower and missing its zip.

When someone asks what happened, I usually tell them, “Do you remember Mark Prior?”

Their response is almost always a sad, knowing, “Oh.”

Both of us—him an all-star pitcher with the Chicago Cubs, me, working to reach the varsity team—fell victim to the same injury: a torn labrum. A piece of fibrocartilage in the shoulder, the labrum cushions the top arm bone, the humerus, against the socket known as the glenoid. Having it securely in place is vital for throwing, and Prior and I had surgery to repair a tear in it.

“The labrum is a pretty simple stabilizer to the shoulder joint,” explained John D. Kelly IV, MD, a professor, surgeon, and the director of Sports Shoulder at Penn Medicine. “It creates a suction seal. It’s like an O-ring on a valve.”

Slate proclaimed the labrum tear as baseball’s “most fearsome injury,” and rightfully so. About half of major leaguers don’t return to form. Prior never did. I didn’t.

But some do. Trevor Hoffman was in the middle of his career as a star relief pitcher with the San Diego Padres when he tore his labrum and had surgery. He returned to be just as dominant and ended up in the Hall of Fame.

And a current example of a thrower excelling after the injury (and surgery) is in a different sport: football.

Andrew Luck missed all of the 2017 season due to a multitude of injuries, chief among them a labrum he tore in 2015. Now, the Indianapolis Colts quarterback is on pace for a career-high in touchdowns.

So why are labrum injuries career-killers for some but just a bump in the road for others?

All of the force generated by an arm whipping around to throw a ball goes through the shoulder joint. If the labrum isn’t sealing right, there could be instability, which translates to pain and a dip in performance. For me, that was a significant dip in velocity and the feeling like someone was prying my arm out of its socket with a barbeque fork.

But instability isn’t just related to pain.

“Stability provides proprioception, or knowledge where the arm is in space,” said Kelly. “It also lets the athlete subconsciously know where exactly to place the ball by the feedback it provides to the brain.”

Andrew Luck
NFL Quarterback Andrew Luck Credit: Wikimedia Commons

If your arm is flying somewhere new, your motion goes out of whack. And as the medical director of the Penn Throwing Clinic, which seeks to address injury risks in players through adjusting their mechanics, Kelly knows the importance of motion. That’s why he’s constantly trying to avoid excessive tightness in the joint, which can be induced by surgery. In fact, Kelly thinks some doctors might be too eager to put torn labrums on the operating table.

“If you treat the MRI and not patients, you often get some very tight throwers because the labral tear did not require fixing,” he said. “And if your shoulder gets too tight after surgery, you can’t come back.”

There’s a new concept of good SLAP (Superior Labral tear from Anterior to Posterior) and bad SLAP. Good SLAP happens when the labrum stretches and results in more range of motion than is typical of experienced throwers. Bad SLAP is more overt separation and extends further down the back of the glenoid, or shoulder socket, and results in instability.

So while bad SLAP usually needs to be fixed by surgery, the issues that caused the labral tear in the first place can potentially be remedied through things like physical therapy.

“It’s often a problem where you need to get a shoulder blade back in place or there are tight hips or quads you need to address to ensure that recurrence of the injury is unlikely,” Kelly said.

Luck’s Luck

Signs point to Andrew Luck having had bad SLAP. But Kelly said it looked like he had a good surgeon and good physical therapy afterward.

Still, there are issues that can linger for a thrower whose labrum has been torn.

In the final play of the Colts’ game against the Eagles earlier this year, Luck was removed to allow the team’s back-up, Jacoby Brissett, a shot at a 54-yard Hail Mary pass.

Could it have been an abundance of caution, a coach wanting to protect his star quarterback? Kelly thinks it’s possible that there was a different reason.

“Every labral tear that I’ve fixed, I would say, results in some motion loss,” Kelly explained. “I would submit that Luck lost some zip and ability to throw far. It may come back in time, however.”

Prevention Through Motion

My zip never did come back. I’m not sure why, but I do know how I got hurt—and how I could have prevented it.

When pitching, my motion brought my hand too far behind my back. Because I extended so far, an inordinate amount of stress was placed on my shoulder joint.

“That likely caused a ‘hurry-up’ motion to get to late cocking, which therefore increased shoulder and elbow strain,” Kelly said.

Luck adjusted his motion both before and after his surgery. While the throwing motion in football is easier on the arm than in baseball, his new motion is much more compact and efficient.

At the Penn Throwing Clinic, throwers are pointed toward improved motions like the one Luck switched to. Kelly’s colleague at the clinic (and its chief scientific consultant), Stephen Thomas, PhD, performs two different analyses in the Human Motion Lab at the Perelman School of Medicine to help establish more efficient and safer mechanics.

Frank Otto
Blog author Frank Otto pitching

The first is a 3-D pitching analysis that uses a slow motion camera to create a detailed view of the thrower’s skeleton at every point in their motion.

“We identify key aspects of the motion that we know have common alterations, then compare their data to normal data from a large number of healthy players,” Thomas said. “When we have large deviations, that’s when we get concerned.”

Additionally, the clinic can provide a “kinetic chain assessment,” which factors in measurements of things like a person’s strength and their full body range of motion to determine what may be factoring into any mechanical deficits in throwing. Then, the clinic team can point out beneficial alterations to the throwing motion along with exercises and stretches to successfully integrate everything.

“That way, it’s long-lasting,” Thomas pointed out.

Making these changes could prevent injuries like a labrum tear. They could also actually keep an existing good SLAP from turning bad.

On top of that, these changes to promote throwing efficiency might make an arm a little more lively, to use an old baseball scouting term.

“Our main focus is to prevent injuries,” Kelly said. “But, if you can successfully adjust everything, you can throw faster. That’s not bad either.”


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