While professional baseball players’ shoulder and elbow injuries have been extensively researched, little is known regarding the prevalence and significance of pectoralis muscle injuries in this population. This study aimed to describe pectoralis muscle injuries in Major League Baseball (MLB) and Minor League Baseball (MLB) players using the official league injury surveillance system (MiLB). To guide future injury prevention techniques, player demographics, return to play (RTP), injury mechanism, throwing and batting side dominance, researchers studied injury rate per athlete exposure. All pectoralis muscle injuries in MLB and MiLB athletes from 2011 to 2017 were compiled using the MLB Health and Injury Tracking System (HITS) database. Researchers, including diagnostic, collected Injury-related data (tear/rupture versus strain), player demographics, injury chronology, surgical intervention requirement, RTP, and mechanism of injury. Sub-analyses of throwing and batting-sided dominance and injury frequency in MLB versus MiLB were conducted.

During the study period, 138 pectoralis muscle injuries were observed (32 MLB, 106 MiLB), with 5 of them being recurring (5 tear/ruptures, 133 strains). Surgical intervention was performed on four athletes (2.9%). About 116 (84.1%) of the 138 injuries resulted in missed days of play, with a mean RTP of 19.5 days. Starting pitchers were the ones that got the most pectoralis injuries (48.1%), with pitching being the most common activity at the time (45.9%). The bulk of injuries (86.5%) occurred during non-contact play. Injuries occurred on the player’s dominant throwing side 87.5% and 81.3% of the time on the player’s dominant batting side. The rate of pectoralis injuries in the MLB regular season (0.584 per 10,000 AE) was not significantly different from the MiLB regular season (0.425 per 10,000 AE) (p=0.1018). Non-contact injuries to the pectoralis muscle are the most common and usually incurred by pitchers. Understanding these injuries can help sports trainers and management manage expectations and make decisions and lead future injury prevention efforts.