Several epidemiologic reports on injury rates in MLB have been published in recent years. Each of these has provided valuable information on specific injuries to MLB players, such as the frequency of injuries to the shoulder, elbow, knee, back, etc., but none have addressed specific injury rates among minor league baseball players (MiLB)1-4. A recent study by Camp, et. al. published in the American Journal of Sports Medicine used the Health and Injury Tracking System (HITS) to analyze 6-years (2011-2016) of injury data on both MLB and MiLB players5-6. The primary purpose of the study was three-fold: 1) to generate a summative analysis of all injuries that occur in MLB and MiLB; 2) to identify the 50 most common injuries; and 3) to generate focused reports and fact sheets on the characteristic of each of those diagnoses.
Readers can access the complete study and a 56-page appendix on-line that provides information on the frequency of each of the 50 most common injuries, player age, level of play, position, throwing- and batting-side-dominance, days missed due injury, injury characteristics, etc. The purpose of this article is to hi-lite several of the important findings of the study.
- 49,550 total injuries were recorded over the 6-year period
- The average number of injuries per year (8,236) remained steady for 6 years
- 91% (45,123) of injuries were non-season ending injuries resulting in 722,176 days out of play, i.e., days missed (DM)
- The average length of DM was 16 days; the median was 6 days
- The most common structure injured was muscle (31%), followed by ligaments (9%) and tendons (8%)
- Pitchers were injured the most (39.1%), followed by infielders (27.1%), outfielders (22.8%) and catchers (11.0%)
- Upper extremity injuries were more common than injuries to any other part of the body; 39% of injuries involved the upper extremity and 35% the lower extremity
- Hamstring strain was the most common injury (6.7%) with 3337 occurrences and 46,706 total DM
- The second most common injury was rotator cuff strain or tear (3.8%), followed by low back strain (2.6%) and biceps tendinitis (2.5%)
- Oblique strains (2.5%) were the 5th most common injury and responsible for 1,249 injuries and 25,249 DM
- Injury to the elbow MCL was the 6th most frequent injury (2.4%) but accounted for the most DM (323,033)
- Most injuries were acute (65.7%), occurred during the season (80.4%) and did not require surgical intervention (90.3%)
- Only 1.6% were reinjuries
- Surgery was required in 6.5% of cases and most of the surgeries, season ending injuries and DM involved the upper extremity
- The most common season ending injuries were elbow UCL (60.0%), superior labrum tears (50.9%), elbow sprain (38.9%), lateral meniscal tear (31.1%), shoulder instability (27%), medial meniscal tear (24.1%), medial elbow epicondylitis (21.3%), ulnar neuritis (20.7%) and forearm flexor/pronator strain (20.0%)
- 3% of injuries were non-contact injuries, the most frequent were contact with the ball (19.4%), ground (9.8%) and another person (4.0%)
- Most of the injuries occurred around home plate (23.4%), on the pitcher’s mound (19.8%) and in the outfield (11.9%)
- Twice as many injuries occurred at 1B (8.6%) and 2B-SS (8.2%) as 3B (3.5%)
- Most injuries occurred while batting (19.7%), pitching (19.3%), fielding (18.0%), throwing (13.9%) and base running (10.8%)
- Only 4.6% of injuries occurred in the weight room or during conditioning
The information in this study should help sports medicine personnel and strength and conditioning coaches identify the most common causes of injury, provide a more reliable estimate of range of days missed associated with each injury and determine appropriate training protocols to help minimize the risk of these common injuries.
- Ahmad, CS, et. al. Major and minor league baseball hamstring injuries: epidemiologic findings from the MLB Injury Surveillance System. Am J Sports Med. 42(6): 1507-1510, 2014.
- Conte, S. et. al. Injury trends in MLB over 18 seasons: 1996-2015. Am J Orthop. 45(3): 116-123, 2016.
- Conte, S. et. al. Disability days in MLB. Am J Sports Med. 29(4): 431-436, 2001.
- Posner, M. et. al. Epidemiology of MLB injuries. Am J Sports Med. 39(8): 1676-1680, 2011.
- Camp, CL, et. al. Summative report of time out of play for major and minor league baseball: An analysis of 49,955 injuries from 2011 through 2016. Am J Sports Med On-Line – enter “Summative Report on Time Out of Play for Major and Minor League Baseball: An Analysis of 49,955 Injuries From 2011 Through 2016”
- Appendix On-Line – enter “Supplemental material for Summative Report on Time Out of Play for Major and Minor League Baseball: An Analysis of 49,955 Injuries From 2011 Through 2016”
Gene Coleman, Ed. D., RSCC-E, FACSM, was the Head S&C Coach for the Houston Astros from 1978-2012 and is currently a strength and conditioning consultant for the Texas Rangers and Professor Emeritus in the Exercise and Health Sciences Program at the University of Houston – Clear Lake.