A Summary of Analysis of Non-Game Injuries in MLB
By Gene Coleman, Ed. D., RSCC*E
A study published in The Orthopedic Journal of Sports Medicine in December of 2019 examined the MLB Health and Injury Tracking System (HITS) medical record database from 2011-2016 to determine how many injuries occur in both MLB and MiLB players that do not occur during the actual game but are related to baseball1. The following hillites some of the information obtained in this massive study. The researchers defined an injury as a primary diagnosis that resulted in at least one day out of play. Injuries were then classified as either “game injuries”, i.e., injuries that occurred during the game or “non-game injuries”. Non-game injuries were defined as injuries that did not occur from the time of the first pitch to the last and included pre-game, post-game, batting practice, workout, weight room, on-premises other and off-premises other. The “other” category including activities such as observing, coaching and other baseball related activities.
Injuries and Days Missed. There were 51,548 total injuries among both MLB and MiLB players in six years (Table 1). Approximately 60% of injuries occurred during a game and 40% were attributed to non-game related factors. Players missed over 700,000 days due to injury and 58% of these were the result of game-related injuries and 42% were the result of non-game related injuries.
|Table 1. Total Injuries, days missed & injury severity among MLB & MILB players.|
Injuries by Level of Play. Because there were significantly more players in MiLB than in MLB, it was not unexpected to find that there were significantly more total injuries (43,036 vs. 8,512), in-game injuries (26,330 vs. 5,817) and non-game (16,506 vs. 2,695) injuries among MiLB players than MLB players (Table 1).
When the researchers looked at the percentage of injuries by level of play, they found that there was a significantly higher percentage of game-related injuries (18%) than non-game related injuries (14%) among MLB players. The opposite pattern, however, emerged in MiLB players with 86% of injuries being non-game related and 82% being game-related. These findings might be attributable, in part, to the fact that the developmental aspect of MiLB often requires players to spend more time on skill training on a daily basis.
Severity of Injury. While there were significantly more total injuries and missed days due to in-game injury than non-game injury, the large number of total injuries that occurred in professional baseball outside of actual games (19,201 non-game injuries) was alarming and signaled a need for further analysis. An examination the severity of game and non-game injuries indicated that, although there were significantly fewer non-game injuries than game injuries, the severity of the injuries was greater among those who sustained a non-game injury (Table 1). A significantly greater percentage of non-game injuries (10.8%) were season-ending injuries compared to the percentage of game-related injuries (8.4%).
When did the injuries occur? The researchers looked at when the injuries occurred in two ways. First, they compared the frequency of injury in spring training, in-season, post-season and off-season and then they looked at frequency of injury by month (April – September). Inspection of Table 2 indicates that there were significantly more total injuries, in-game injuries and non-game injuries during the season than at any other time of the year. This was not unexpected due to the fact that the are significantly more days during the season than in any other part of the year.
Spring training provided interesting findings. Data indicated that there were significantly more non-game injuries (4,970) than in-game injuries (3,160) during spring training. Approximately 25% of injuries reported during spring training were non-game injuries and only 10% were game-related injuries. This might be attributable to ….
The relatively low number of total injuries, in-game injuries and non-game injuries during the post-season was also not unexpected. While relatively few MLB and teams and players are involved in post-season competition, a higher percentage of in-game injuries (86%) was reported than non-game injuries (62%).
|Table 2. When did injuries occur?|
|Season||Total Injuries||In-Game Injuries||Non-Game Injuries|
Inspection of Table 3, indicates that there was a progressive increase in total injuries and in-game related injuries from April thru August. The number of non-game injuries was fairly constant during this time period. There was a gradual decrease in total injuries and in-game and non-game injuries in the month of September.
|Table 3. Which months of the season did injuries occur?|
|Month||Total Injuries||In-Game Injuries||Non-Game Injuries|
Injuries by position. Inspection of Table 4 indicates that within MLB, pitchers (starters and relievers) had significantly high percentages of non-game related injuries than game-related injuries. Approximately 29% of injuries among MLB pitchers were non-game related and 20% were game related (Table 5). A similar pattern existed for MiLB pitchers among which 24% experienced non-game related injuries and 14% experienced game related injuries (Table 5).
The pattern was reversed for position players (Table 4). Approximately 9% of the injuries to catchers were game-related and 6% were non-game related. Approximately 31% of infielder injuries were game-related and 23% were no-game related. A similar finding was observed among outfielders. Approximately 26% of outfielders experienced game-related injuries and 19% experienced non-game related injuries.
|Table 4. MLB Injury by Position|
The results were similar for MiLB players (Table 5). Pitchers had significantly more non-game related injuries than game related injuries, and position players had significantly more game related injuries than non-game related injuries. It’s also important to note that starting pitchers combined for a large majority of the non-game related injuries. Approximately 40% of the injuries to starting MLB pitchers were non-game related, and 54% of the injuries to starting MiLB pitchers were non-game related.
|Table 5. MiLB by Position|
Injuries by Activity. The frequency of injury attributable to different activities is presented in Table 6. The data in this table indicate that approximately 86% of total injuries was related to throwing, pitching, hitting, fielding and base running, while only 5 percent was related to conditioning and 9% was related to other factors. The percentage of in-game injuries related to pitching (22%) was significantly greater than then percentage of non-game pitching injuries (11%). Likewise, the percentage of in-game hitting injuries (24%) was significantly greater than the percentage of non-game hitting injuries (12%), and the percentage of in-game base running injuries (22%) was significantly higher than the percentage of non-game base running injuries (4%).
On the other hand, the percentage of non-game related injuries attributable to throwing (30% vs. 5%), conditioning (14% vs. 2%) and other (18% vs. 3%) was significantly higher than the percentage of game-related throwing, conditioning and other injuries.
|Table 6. Injury by Activity|
Inspection of Table 7 indicates that most injuries were non-contact related and were significantly more likely to occur during non-game situations (73%) than in-game situations (46%). Contact-related injuries more likely to occur in-game (49%) than in non-game situations (12%).
|Table 7. Injury Mechanism|
Conclusions and Practical Application
- Non-game injuries related to baseball participation make up over one-third of the total injuries incurred by professional baseball players and accounted for over 100,000 days missed over five seasons.
- Non-game injuries are more likely to occur in MiLB athletes and pitchers.
- MiLB players sustained significantly more non-game injuries than MLB players which is attributable to the fact that there are more MiLB players, and MiLB players are engage in more practice time including extended spring training and instructional league. MiLB players attempting to advance may also be conditioning, training, or practicing at a higher intensity or volume than the body is prepared to handle.
- Starting pitchers made up the majority of non-game-related injuries. Most of these injuries were either pre-game or workout injuries. It is important to note that most of the workout injuries were reported as throwing injuries, not weight room or conditioning injuries. While starting pitchers are exposed to fewer games than position players, they are often exposed to more innings. While pitch counts are recorded during games, it is possible that some starting pitchers might be throwing too many pitches during bullpen sessions or during their throwing workouts between starting appearances. To ensure that an accurate record of the volume of work performed by pitchers, it is important that the number of pitches thrown in the bullpen and during a workout should be included in the total pitch count for each starting and relief pitcher.
- Most injuries (80%) in pro baseball players occur during the 162-game season.
- More than 25% of non-game injuries occur during spring training which might be attributable, in part, to a sudden increase in workload intensity and/or volume and/or improper physical preparation for spring training.
- The higher injury rate in April might be related to an increase in non-game activities coming out of spring training and the increase in injuries in September might be due to general body fatigue and accumulated microtrauma.
- Although most of non-game injuries were categorized as “workout injuries”, further examination of the injury data indicated that only 25% of the workout injuries were related to conditioning and weight training and 75% were related to throwing.
- The authors proposed an improved tracking database system to better understand non-game injuries. They proposed that injuries first be divided into the following four major categories: 1) pregame to first pitch; 2) fist pitch to last pitch; 3) post-game, i.e., after last pitch until leaving stadium; and 4) other to include time away from the stadium, relief pitcher in bullpen during a game, or position player hitting in cage during and after a game. After the four major categories, injuries should be sub-classified into the following minor categories: 1) batting practice, 2) throwing off the mound at any time, 3) any throwing that does not occur on the found, 4) fielding practice and 5) workout to include weight room activity and non-weight room stretching, conditioning, sprinting, distance running, etc.
- Esquivel, A., et. al., Analysis of non-game injuries in Major League Baseball, Orthopedic Journal of Sports Medicine, December 2019. To read the full article, go to: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6935766/
Gene Coleman was the Head S&C Coach for the Houston Astros from 1978-2012 and is currently a S&C consultant for the Texas Rangers, Professor Emeritus in the Exercise and Health Sciences Program at the University of Houston – Clear Lake and Website Education Manager baseballstrength.org.