Injuries and Baseball: The Use of Infrared Thermography

Baseball is one of the most biomechanically demanding sports, particularly in throwing and batting movements. Its high injury incidence has sparked scientific interest in the epidemiology of its injuries. This knowledge opens the door to integrating new technologies, such as infrared thermography (IRT).

In this article, we address the most relevant data—published by prominent authors such as Bakshi, Bullock, and Ledbetter, among others—regarding injury incidence in baseball, the most frequent risk factors, and how thermography could contribute in this context.

Injuries in Baseball: what we know and why it matters

Various reviews and epidemiological studies agree that overuse injuries in baseball predominantly affect the upper limb—especially the shoulder and elbow—as a result of the high, repetitive mechanical stress involved in throwing motions (Oyama, 2012; Mine et al., 2021).

One study reported that 14–20% of all injuries in adult amateur players occur in the shoulder (Mine et al., 2021), while among youth pitchers, 26% have reported elbow pain (Bullock et al., 2018). In professional players, elbow injuries can account for up to 22% of all injuries (Bullock et al., 2018; Oyama, 2012).

These injuries have a direct impact on performance, as well as economic implications for clubs: loss of training or games, need for surgical interventions, and, in severe cases, the premature end of a sporting career (Bakshi et al., 2020; Mine et al., 2021).

Injuries in baseball—especially those resulting in placement on the Major League Baseball (MLB) disabled list (DL)—are common and remain a persistent, significant problem. The overall injury rate in the MLB was 3.61 per 1,000 athlete exposures between 2002 and 2008, with a significant 37% increase in injuries from 2005 to 2008. The highest in-season injury rate occurs in April (5.73/1,000 exposures), and the lowest in September (0.54/1,000 exposures).

Where, How, and Why Do Players Get Injured?

High-level reviews have enriched the epidemiological data, allowing the identification of patterns and risk factors. Below is a summary of the most relevant findings:

Injury Location

• Shoulder (rotator cuff, posterior capsule, SLAP lesions, impingement).
• Elbow (ulnar collateral ligament – UCL –, medial epicondylitis, osteochondritis dissecans).
• Less frequently: wrist, lower back, hamstrings, and lumbar region.

Injury Types

• Overuse injuries predominate over traumatic ones (Mine et al., 2021).
• High incidence of injuries associated with repetitive throwing, especially in pitchers and catchers.

Most Studied Risk Factors

• Glenohumeral internal rotation deficit (GIRD) and loss of overall mobility (Bullock et al., 2018).
• High throwing volume or weekly/session load spikes (Bakshi et al., 2020).
• High pitching velocity (Chalmers et al., 2019).
• Poor throwing mechanics (Oyama, 2012).
• Weakness in external rotators and scapular musculature (Bullock et al., 2018).

Reduced hip mobility and core weakness, affecting the kinetic chain (Mine et al., 2021).

Differences in Injuries: Pitchers vs. Fielders/Batters

Pitchers:

• Experience injury incidence rates 34% higher than position players (Fielders/Batters).
• Upper extremity injuries predominate, accounting for 67.0% of their injuries, while lower extremity injuries account for 16.9%.
• Shoulder and elbow injuries have the highest incidence at all levels (high school, college, and professional).
• Shoulder injuries accounted for 75.0% and elbow injuries for 63.9% of average seasonal injuries in pitchers.
• Pitchers spend significantly more days on the DL for upper extremity injuries (an average of 74.25 days) than for lower extremity injuries (41.26 days).
• Pitchers’ injuries tend to be more severe. For example, Oyama et al. (2012) reported that 73% of high school injuries requiring surgery were sustained by pitchers. UCL injuries are common, and their rates continue to rise at all competition levels.

Fielders/Batters:

• Have a significantly higher proportion of lower extremity injuries (47.5%) compared to pitchers.
• Lower extremity injuries in position players include foot/ankle (17.1%), knee (24.4%), hamstrings (27.0%), and groin (5.7%).
• Spend more days on the DL for upper extremity injuries (54.16 days) than for lower extremity injuries (44.59 days).
• Injury Similarities:
  • Spinal and core musculature injuries are common in both groups, representing 11.7% of total DL injuries.
  • Most injuries occur in the early months of the season, suggesting the importance of proper conditioning and training during preseason and early season.

Workload and Injury Relationship (Mainly Pitchers):

Increased pitching workload is associated with greater risk of arm pain, injury, and fatigue in Little League and high school pitchers. However, consensus is limited for college and professional pitchers.

Throwing with arm fatigue appears to be a significant risk factor regardless of pitch count. Some authors, such as Bakshi et al. (2020), note that pitchers who throw more than 400 pitches per season may experience supraspinatus strength reduction. While this was observed in developing players, less experience in professional pitchers has also been linked to UCL injuries.

Additionally, higher pitching velocities (especially fastball, change-up, and curveball) are associated with a greater risk of UCL injury in professional pitchers (Oyama, 2012).

Some authors propose that total pitch count—including bullpen warm-ups and between-inning throws—could be a more accurate measure of accumulated workload. Injured professional pitchers were also found to have thrown significantly more warm-up pitches.

Infrared Thermography in Baseball.

Despite baseball’s high level of specialization and the evidence on injuries—as well as the need for information on players’ internal load—the application of infrared thermography in this sport is limited. However, strong arguments support its integration, and the use of thermography in other sports and health contexts highlights its great potential for baseball as well.

Potential Benefits of Thermography in Baseball

• Assessment of thermal asymmetries, especially relevant in areas such as shoulders, elbows, or rotator muscles, which could reveal information about condition and imbalances for various reasons.
• Monitoring of injury evolution, allowing for assessment of how a specific region is responding after an injury, treatment, post-training, or post-game.
• Load monitoring in a non-invasive way.
• Support in decision-making for return-to-play.

Thermography has proven useful in sports (such as soccer, American football, hockey, basketball, etc.) as a tool for internal load monitoring, diagnostic support, and fatigue control, among others. Given baseball’s specific mechanics and high repetitiveness, the sport has the conditions for its implementation.

Final messages and applications

The epidemiology of baseball injuries is well-documented, and science has identified multiple risk factors that allow prevention to be addressed from an individualized perspective.

In light of this evidence, infrared thermography stands out as an interesting tool that can facilitate physiological monitoring, load control, and decision-making.

Efficient, rigorous integration into technical and medical staff routines could improve player health and performance on an individual basis.

References

• Bullock, G. S., Faherty, M. S., Ledbetter, L., Thigpen, C. A., & Sell, T. C. (2018). Shoulder range of motion and baseball arm injuries: A systematic review and meta-analysis. Journal of Athletic Training, 53(12), 1190–1199. https://doi.org/10.4085/1062-6050-322-17
• Chalmers, P. N., Erickson, B. J., Ball, B., Romeo, A. A., & Verma, N. N. (2019). Risk factors for ulnar collateral ligament injury in professional and amateur baseball players: A systematic review with meta-analysis. Journal of Shoulder and Elbow Surgery, 28(1), 186–195. https://doi.org/10.1016/j.jse.2018.09.002
• Bakshi, N. K., Inclan, P. M., Kirsch, J. M., Bedi, A., Agresta, C., & Freehill, M. T. (2020). Current workload recommendations in baseball pitchers: a systematic review. The American Journal of Sports Medicine, 48(1), 229-241.
• Mine, K., Milanese, S., Jones, M. A., Saunders, S., & Onofrio, B. (2021). Risk factors of shoulder and elbow injuries in baseball: A scoping review of three types of evidence. Orthopaedic Journal of Sports Medicine, 9(12), 23259671211064645. https://doi.org/10.1177/23259671211064645
• Oyama, S. (2012). Baseball pitching kinematics, joint loads, and injury prevention. Journal of Sport and Health Science, 1(2), 80–91. https://doi.org/10.1016/j.jshs.2012.06.004