A New Baseball Season Means New Thoracic Outlet Syndrome Cases

We are one month into a new major league baseball season. Like many baseball fans, I am excited and intrigued by the new rules, by the surprising rookies and teams, and by the promise of success every team enjoys in a new season.

However, as a thoracic outlet syndrome specialist, I am also intrigued by the growing awareness of neurogenic thoracic outlet syndrome among these very gifted and hard-working athletes. Over the past decade or two, I have watched with interest as awareness of thoracic outlet syndrome in baseball players has grown. Every year, it seems more players are receiving the diagnosis of neurogenic thoracic outlet syndrome than in prior years. I am hopeful that this trend continues, and with it increasing awareness of thoracic outlet syndrome in the general community.

Thoracic outlet syndrome (TOS) is a group of related disorders that occur when compression of blood vessels or nerves occurs in the space between the collarbone and the first rib (the thoracic outlet), accompanied by a broad range of symptoms. When the nerves are compressed and the patient is symptomatic from this compression, neurogenic thoracic outlet syndrome is present.

Baseball players are susceptible to developing neurogenic thoracic outlet syndrome due to the repetitive stresses and high loads placed on their dominant shoulder and arm. This is especially true for pitchers.

Pitching a baseball requires a string of coordinated, synchronous and sequential motions. A baseball pitcher utilizes both legs, the pelvis, trunk, shoulder, elbow, hand, and wrist. The pitching motion has been widely studied, and is currently recognized as having 6 distinct phases:

• Windup
• Stride
• Cocking
• Acceleration
• Deceleration
• Follow-through

While the pitching motion is beyond the scope of this article regarding thoracic outlet syndrome in baseball players, a few key elements can be emphasized. Pitching involves one of the fastest human motions (perhaps the fastest). Different muscles are activated during different phases of the pitching motion. Injuries affect different muscles during different phases, each caused by different mechanisms. Shoulder injuries are the most common injury in pitchers, while elbow injuries are the second most common injury. There exists scant literature on the causes or incidence of brachial plexus injuries in baseball pitchers.

Why Are Baseball Players Prone To Developing Thoracic Outlet Syndrome?

Baseball players may be at a higher risk of thoracic outlet syndrome due to the unique demands and mechanics of the sport. Let us consider what factors may contribute to thoracic outlet syndrome in baseball players.

Repetitive Motion and High Forces

Many overhead athletes are at increased risk for developing thoracic outlet syndrome. These include not only baseball players, but swimmers, volleyball players, and rock climbers, among others. Some of these athletes perform numerous repetitive overhead activities such as throwing or swimming strokes. Other athletes assume overhead positioning during periods of maximal muscle contraction, such as rock climbers. Some athletes experience both mechanisms.

Baseball players often perform repetitive overhead motions at maximal exertion when throwing the ball. Baseball pitchers, in particular, perform a high percentage of repetitive overhead actions under maximum stress to achieve high-velocity throwing. As a result of these actions, these athletes experience unusual and asymmetric stresses on their joints, muscles, and supporting soft tissues. In some pitchers, these mechanisms cause abnormal positioning of the scapula and supporting muscles, which in turn leads to abnormal clavicular positioning. If the clavicle approaches the first rib too closely, it may cause compression of the brachial plexus. When this becomes symptomatic, neurogenic thoracic outlet syndrome occurs. In addition, irritation of the brachial plexus may result from anomalous muscles of the scalene triangle, also presenting as neurogenic TOS. Less commonly, compression and damage to the subclavian artery or subclavian vein may occur. When this damage leads to an aneurysm or blood clot, arterial thoracic outlet syndrome or venous thoracic outlet syndrome is present. In summary, the repetitive and large stresses faced by high-performance baseball players can cause strains on specific muscle groups or compression/tension on the brachial plexus, resulting in edema, inflammation, and scar tissue formation in the shoulder and neck area. Eventually, this may lead to the compression of the nerves and blood vessels in the thoracic outlet. If not promptly recognized and adequately addressed, neurogenic thoracic outlet syndrome may develop.

Poor or Inconsistent Throwing Mechanics

Improper throwing mechanics can place excessive strain on the shoulder and neck muscles, increasing the risk of developing thoracic outlet syndrome.

Poor Pitching Mechanics may Include:

• Inadequate warm-up or insufficient stretching
• Insufficient stretching
• Inconsistent mechanics arm positioning during the throwing motion
• Different motions are required for different pitches
• Different mechanics are used in a full wind-up pitch versus the abbreviated ‘stretch’ pitch when men are on base.

At the elite level, baseball pitchers push themselves to the edge of the performance envelope. One can imagine how difficult it is for these athletes to maintain consistent form through every throwing motion. In addition, a pitcher may maintain good throwing mechanics early in a game, only to lose this consistency under conditions of fatigue later in a game. Further, the stress of competition at this high level, often in front of a considerable crowd and a national television audience, may distract from typical performance.

Scapular Dyskinesia

Normally, the shoulder blade, collarbone, and upper arm bone move in a predictable pattern, known as scapulohumeral rhythm. Disturbance of this pattern, also called ‘Scapular dyskinesia,’ (i.e., abnormal movement of the shoulder blade) may develop in baseball players. This abnormal movement can lead to increased pressure on the structures of the thoracic outlet, the rotator cuff, or the labrum. Disorders of the bones, joints, muscles or nerves, or decreased flexibility may contribute to abnormal scapulohumeral rhythm.

Hyperabduction

Hyperabduction of the arms refers to positioning of the arm more than 90 degrees to the front or to the side from the resting neutral position. Hyperabduction occurs repeatedly during the throwing motion. This extreme arm positioning can cause compression of the thoracic outlet structures by bringing the collarbone and first rib closer together.

Trauma

All athletes face an increased risk of trauma due to their high-level competition with other athletes. Direct trauma to the collarbone, shoulder, or neck area can trigger inflammation in the surrounding soft tissues of the thoracic outlet, increasing the risk of thoracic outlet syndrome. Fractures of the collarbone or first rib may heal with a large bony callus or bump, reducing the space needed for the brachial plexus or blood vessels to pass through the thoracic outlet. Baseball players may experience this trauma from collisions or falls during gameplay.

Active Baseball Players Diagnosed with Thoracic Outlet Syndrome

Mike Zunino

In 2022, Cleveland Guardians catcher Mike Zunino was diagnosed with neurogenic TOS. Zunino underwent surgery and is back with the major league team. However, he has suffered a slow start, batting 0-for-27 with 21 strikeouts in May. In addition, he is struggling on defense, with opposing baserunners stealing successfully on 45 of 53 attempts against Cleveland Guardian catchers.

Nick Nastrini

Nick Nastrini is a hard-throwing right-handed pitcher who played for the UCLA Bruins. As a freshman in 2019, Nick underwent surgery for thoracic outlet syndrome. Since then, he had been recognized as a prospect with great potential, but who had issues with control. The Los Angeles Dodgers drafted him in the 4th round with the hope of resolving his control issues. He is currently pitching at the AA level with the Tulsa minor league team of the Dodger organization.

Cole Henry

Washington Nationals pitcher Cole Henry underwent TOS surgery in August 2022 after years of dealing with arm issues. The long-term impact of the injury on Henry’s career is still uncertain. You can read a very detailed story about Cole’s journey here: Surgery removed this Nats prospect’s rib. It might also give him a career.

Jared Walsh

Los Angeles Angels first baseman Jared Walsh first noted symptoms of neurogenic TOS in 2019, but continued to play. He ultimately earned a spot on the America League All-Star team in 2021. Unfortunately, his symptoms worsened and he suffered through a difficult 2022 season. In 2022, he hit 15 home runs and 18 doubles, down from 29 home runs and 34 doubles in 2021. He drove in 44 runs in 2022, down from 98 RBIs in 2021. Jared underwent thoracic outlet surgery in late 2022. He finally returned to the big league Angels’ lineup this past Saturday, May 20.

Stephen Strasburg

Washington Nationals pitcher Stephen Strasburg was drafted number 1 overall in the 2009 baseball draft. He was one of the most highly regarded pitchers to come out of the draft in many decades. He met the expectations with a great early career, and ultimately won the 2019 World Series MVP. However, he struggled with injuries the following year, making only 2 appearances in 2020, and he underwent carpal tunnel surgery in August 2020. Stephen then made only 5 appearances in 2021. He was eventually diagnosed with neurogenic TOS, and underwent surgery in August of that year. After a long rehab, Stephen returned to the Nationals in June 2022, when he pitched just under 5 innings. He suffered a recurrence of symptoms, and has not pitched since. His future remains unclear.

Daniel Bard

Daniel Bard rose to the majors in 2009 with the Boston Red Sox. He pitched his way to a stellar ERZ of 1.93 in 2010, often reaching 100 mph with his fastball. But things fell apart when he lost his control in late 2011 and in 2012. Prior to the 2014 season, Daniel underwent thoracic outlet syndrome surgery. Bard struggled with several organizations, and he retired from baseball in 2017. Amazingly, Daniel returned to the major leagues with the Colorado Rockies in 2020, earning the National League’s Comeback Player of the Year Award. Early this year, he has a 0.82 ERA with the Rockies.

Weston Wilson

Weston Wilson is a third baseman in the Philadelphia Phillies minor league organization, formerly in the Milwaukee Brewers minor league organization. Weston underwent surgery for thoracic outlet syndrome in 2021.

Brendan McKay

McKay was selected by the Tampa Bay Rays 4th overall in the 2017 draft, and has been with the organization since as a pitcher and designated hitter. In 2021, Brendan underwent thoracic outlet syndrome surgery, and in 2022, he underwent Tommy John surgery. He is currently in the Rays’ minor league organization.

Trevor Rosenthal

Trevor Rosenthal has pitched with several major league teams, including the Athletics, the Giants, the Tigers, and the Brewers. He underwent surgery for thoracic outlet syndrome in 2021, then missed the entire 2022 season with a strain of the latissimus dorsi muscle. He is currently in the Detroit Tigers’ minor league organization.

Nick Burdi

Nick was drafted by the Minnesota Twins in 2014. While still in the minor leagues, Nick underwent Tommy John surgery twice, and was picked up by the Philadelphia Phillies, then traded to the Pittsburgh Pirates organization. He made it to the major leagues late in the 2018 season. In June 2019, Nick was diagnosed with thoracic outlet syndrome and underwent surgical treatment. He pitched briefly at the major league level for the Pirates in 2020, but required a third Tommy John surgery, and was released. He spent some time in the San Diego Padres organization, but did not pitch in 2022. Nick was picked up by the Chicago Cubs in 2023, and performed quite well as a relief pitcher at their AAA level. Finally, he was promoted to the major league club, and pitched for the first time at this level since 2020, earlier in May of this year.

Drew Verhagen

Relief pitcher Drew Verhagen was drafted by the Detroit Tigers in the fourth round of the 2012 draft. He made it to the major leagues for a single day in 2014. He made it back to the team in 2015 and 2016, but was diagnosed with thoracic outlet syndrome in 2016. Drew underwent surgery for thoracic outlet syndrome in August 2016. Drew bounced between the minor leagues and major leagues until Detroit released him after the 2019 season. He spent two years pitching in Japan, and became a free agent after the 2021 season. In 2022, VerHagen signed a two-year contract with the St. Louis Cardinals.

Antoine Kelly and Cody Bradford

Two pitchers high in the Texas Rangers minor league organization who have undergone surgery for thoracic outlet syndrome.

Carson Ragsdale

Carson had Tommy John surgery in 2019, and was drafted by the Philadelphia Phillies in 2020. He underwent surgery for thoracic outlet syndrome in 2022, and is now in the San Francisco Giants’ minor league organization.

Notable Inactive Baseball Players Diagnosed with Thoracic Outlet Syndrome

Josh Beckett

Josh Beckett’s story provides one of the most inspiring success stories for a baseball player with thoracic outlet syndrome. Beckett played for 3 teams over a 15-year career, including the Florida Marlins, the Boston Red Sox, and the Los Angeles Dodgers. Beckett was named to an All-Star team 3 times during his career. He was a critical part of two World Series champions, and was named MVP of the 2003 World Series with the Florida Marlins.

In 2013, while with the Dodgers, Josh was diagnosed with thoracic outlet syndrome, and he underwent surgery, after which he missed the remainder of the 2013 season. He returned to the team in 2014, and pitched a no-hitter against the Philadelphia Phillies.

Matt Harrison

Matt Harrison was drafted by the Atlanta Braves in the 2003 draft, but he ended up pitching for the Texas Rangers from 2008 to 2015. He was an All-Star in 2012. Harrison had TOS Surgery on the left in 2009, and on the right in 2013.

Matt Harvey

Matt Harvey was selected by the New York Mets with the 7th overall pick in the 2010 baseball draft. He was promoted to the major leagues in 2012, and developed into a regular starter in 2013. He missed the entire 2014 season due to Tommy John surgery. In 2015, Harvey emerged as one of the best pitchers in baseball on a revitalized Mets team that made it to the World Series. However, Harvey struggled throughout the 2016 season, and in July he underwent surgery for thoracic outlet syndrome.

After a lengthy recovery process, Harvey returned to professional baseball and played for several teams, including the Cincinnati Reds, Los Angeles Angels, Baltimore Orioles, and Kansas City Royals. He never reached his prior level of performance, and on May 5, 2023, Harvey announced his retirement from baseball.

J.R. Richard

J.R. Richard was an intimidating, 6’8” tall pitcher for the Houston Astros in the late 1970s. He had reached the peak of his career in 1980. From The NY Times, ‘In 1980, Richard was coming off consecutive seasons of 300 strikeouts. He was 10-4 with a career-best 1.90 earned run average at the time of his stroke. He had allowed only two home runs in 17 starts, and batters were hitting .166 against him.’

In July 1980, while playing catch on-field in the Houston Astrodome, Richard collapsed. He was found to have arterial thoracic outlet syndrome, with a blood clot traveling to his brain, causing a stroke. Richard never pitched in the major leagues again.

Kenny Rogers

Kenny Rogers pitched for 6 different teams over a 20-year career, from 1999 to 2008. He played in two World Series, with the Yankees in 1996, and with the Detroit Tigers in 2006. Kenny pitched the 14th-ever perfect game in baseball history in 1994 against the California Angels. Rogers underwent left thoracic outlet syndrome surgery in 2001. Fortunately, Rogers is one of a few major league TOS success stories, as he recovered from TOS and played for seven more seasons until he retired in 2008.

Takeaway Message

Thoracic outlet syndrome occurs surprisingly frequently in high-level baseball players, particularly in baseball pitchers. We are currently witnessing a rising tide of awareness of thoracic outlet syndrome in baseball players, which I consider both belated and deserved. In my opinion, it is important to recognize, diagnose, and treat thoracic outlet syndrome promptly in these athletes, for their futures, for the benefit of the sport itself, and for the benefit of all baseball fans.