Objectives: The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is yet to be fully elucidated. The primary aims of this study were to assess various throwing metrics through a structured long-toss program using wearable technology and to quantify the intra and inter thrower variability of these metrics at each stage of throwing. Methods: This was a descriptive laboratory study in which 60 high school and collegiate pitchers participated in a predetermined, structured, progressive long-toss program. All players wore a motusBASEBALL sleeve (Motus Global, Inc.; Rockville Centre, NY), which measured arm slot, arm velocity, shoulder rotation, and elbow varus torque. Radar guns were used to measure ball velocity. These metrics were compared within and between all pitchers at each of the following throwing distances: 90 ft, 120 ft, 150 ft, 180 ft, and maximum effort mound pitching. Intra- and inter- thrower reliabilities were calculated for each throwing metric at every stage of the program. Excellent intra-thrower reliability was defined by an Intra-class coefficient (ICC) >0.750. Acceptable inter-thrower reliability was defined by a Coefficient of Variation (CV) <5%. Results: Ball velocity significantly changed at each progressive throwing distance, but this did not consistently correlate with an increase in elbow torque. Pitching from the mound did not place more torque on the elbow than throwing from 120 ft and beyond. Intra-thrower reliability was excellent throughout the progressive long-toss program for each throwing metric. Ninety-one percent of throwers had acceptable inter-thrower reliability for ball velocity, whereas only 79% of throwers had acceptable inter-thrower reliability for elbow torque. Conclusion: Based on trends in elbow torque, it may be practical to incorporate pitching from the mound earlier in the program (once a player is comfortable throwing from 120 ft). Ball velocity and elbow torque do not necessarily correlate with one another, so a degree of caution should be exercised when using radar guns to estimate elbow torque. Given the variability in elbow torque between throwers, some athletes would likely benefit from an individualized throwing program.
Does Perceived Effort Match Actual Measured Effort During Baseball Long Toss Programs?
Objectives: Progressive throwing programs are a mainstay of rehabilitating the throwing athlete after injury or surgery. Athletes are commonly asked to throw at reduced levels of effort (i.e. “50% effort”, ”75%,” etc) to minimize stress to healing tissues. However, it is unknown whether players’ perceived exertion matches actual exertion. The purpose of this study was to determine whether decreased effort correlates with decreased throwing metrics, whether metrics decrease to a predictable degree, and to quantify variability of these metrics within a given athlete when attempting to throw at sub-maximal effort. Methods: Sixty healthy, high school and collegiate baseball pitchers participated in a structured throwing program. After warming up, each pitcher was asked to throw five, max effort long toss throws at a distance of 120 feet. Afterwards, they were asked to give 5 throws at both 75% effort and 50% effort from the same distance. A motusBASEBALL sleeve (Motus Global, Inc.; Massapequa, NY) was worn by all players, which measured arm slot, velocity, shoulder rotation, and elbow varus torque (Nm). Ball velocity was measured in miles per hour (MPH) using a radar gun. The observed changes in throwing metrics were compared to one another across each of the throwing scenarios using a general estimating equation to control for multiple comparisons. They were also compared to the expected change to see if a decrease from 100% effort to 75%, and then to 50% resulted in proportional decreases in elbow torque and ball velocity. Intra-thrower variability was determined for each throwing metric at each degree of effort, and these results are reported using intra-class correlation coefficients (ICC) where an ICC > 0.75 was considered to represent excellent agreement. Results: Mean elbow torque decreased as players decreased their perceived effort from 100% (72.7 Nm) to 75% (67.3 Nm) to 50% (62.s Nm) (p<0.001). Mean ball velocity also decreased as they progressed from 100% effort (77.8 MPH) to 75% effort (66.5) to 50% effort (60.3 MPH) throws (p<0.001). However, these observed decreases in torque and velocity were much smaller in magnitude than the decreases in perceived effort. During the 75% effort throws, torque and velocity were not reduced to 75% of max. Instead, elbow torque was only reduced to 93.3% of max, and velocity dropped to 86.1% of max. Similarly, for the 50% effort throws, torque remained 86.5% of max effort torque, while velocity remained 78.1% of max. Accordingly, for every 25% decrease in perceived effort, torque only decreased 7%, and velocity only decreased 11%. These observed differences were all significantly different than the expected differences (p<0.001 for all). Intra-thrower reliability was considered excellent for all metrics within each throwing scenario: max effort, 75% effort, and 50% effort (ICC>0.75 for all). Conclusion: Measured effort was significantly greater than perceived effort during this standardized throwing program for all metrics tested. This is especially true for ball velocity and varus elbow torque. Ultimately, when players throw at what they perceive to be “reduced effort,” their actual throwing metrics do not decrease at the same rate as their perceived exertion. This has significant implications for throwers during the rehabilitation process as their elbows are likely experiencing more stress than desired. Clinicians and coaches must be aware and may want to consider transitioning to more objective measures of effort during rehabilition.
Revision Ulnar Collateral Ligament Reconstruction in Professional Baseball: Current Trends, Surgical Techniques, and Outcomes
Objectives: Ulnar collateral ligament (UCL) reconstruction of the elbow is a commonly performed surgery on professional baseball pitchers. Recent reports have suggested that revision rates are on the rise and may be higher than previously thought. The purpose of this study is to provide a comprehensive report on current trends, surgical techniques, and outcomes of revision UCL reconstructions performed on professional baseball pitchers between 2010 and 2016. Methods: The Major League Baseball (MLB) Health and Injury Tracking System (HITS) was used to compile records of all revision UCL reconstructions performed on professional baseball pitchers between 2010 and 2016. Player data and outcomes were obtained from HITS while surgical details were obtained from operative reports. Descriptive statistical analysis was performed on epidemiologic data. Outcomes (return to play rates, return to play times, subsequent injuries, and subsequent surgeries) were compared across the most common surgical techniques (Docking vs. Modified Jobe) and graft sources (palmaris longus autograft vs. hamstring autograft). Results: A total of 69 professional baseball pitchers underwent revision UCL reconstruction from 2010 to 2016 at an average of 1,424 days (47 months) after their primary surgery. There was a trend toward increasing numbers of revision surgeries over time (R2=0.441; p=0.104). The most commonly used tunnel configuration was the Modified Jobe technique (n=41, 59.4%) and the most common graft utilized was hamstring autograft (n=34, 49.3%). 76.6% of pitchers were able to return to play (RTP) and 55.3% were able to return to the same level of play. Mean time to RTP in players with a palmaris longus autograft was 436 days versus 540 days for hamstring autograft (p=0.108) and the mean time to RTP in players was 423 days for the Docking technique versus 519 days for the Modified Jobe technique (p=0.296). Similar rates of subsequent injuries and surgeries were noted between the two revision techniques and two most commonly used graft constructs. Conclusion: This report detailing revision UCL reconstruction amongst professional baseball pitchers showed a trend towards increasing numbers of revisions being performed, a finding consistent with other recent studies. The overall return to play percentage was higher than previously reported (76.6%); however, significantly fewer (55.3%) players returned to the same level of play. This work also demonstrated decreased return to play times (n=484 days, SD: 117.3) compared to other investigations. The Modified Jobe was the most commonly used surgical technique and the two most commonly used graft constructs were hamstring autograft and palmaris longus autograft. Although this analysis did not reveal any statistically significant comparative differences between surgical techniques or graft constructs, future studies involving head-to-head comparisons of these surgical variables, specific to revision UCL reconstruction, may be helpful in improving player outcomes and career performance.
Epidemiology and Impact of Hand and Wrist Injuries in Major and Minor League Baseball
Background: Professional baseball players are at risk of acute and chronic injuries to their upper extremities. Methods: Major League Baseball’s Health and Injury Tracking System, a prospective injury surveillance system, was used to identify and characterize all hand and wrist injuries sustained by all Major League Baseball (MLB) and Minor League Baseball (MiLB) players during the pre-, regular, and postseason throughout 2011-2016. Injuries were included if they resulted in at least 1 day out of play and were sustained during standard baseball activities. Days missed were defined as the time between injury and the first time in which a player was cleared to return to play. Results: During the study period, there were 4478 hand and 1748 wrist injuries throughout MLB and MiLB, which resulted in a total of 105 246 days out of play. This was equivalent to the length of 575 individual MLB player seasons, and the mean days missed per injury was 17 days. Most injuries were traumatic in nature, with 43% (n = 2672) of players injured after being hit by a baseball that mainly occurred during batting (n = 2521; 40%). Injuries that most frequently required surgical intervention were hook of hamate fractures (72%) and scaphoid fractures (60%). Conclusions: Understanding the epidemiology and impact of hand and wrist injuries in MLB and MiLB players may lead to improved management of these injuries and reduce time away from play. Most importantly, preventive measures and/or enhanced protective gear may be developed to minimize these types of injuries in MLB and MiLB.
Baseball Pitchers’ Perceived Effort Does Not Match Actual Measured Effort During a Structured Long-Toss Throwing Program
Background: During rehabilitation throwing programs, baseball players are commonly asked to throw at reduced levels of effort (ie, 50% effort, 75% effort, etc) to moderate stress to healing tissues. It is currently unknown how changes in players’ perceived exertion compares with changes in actual exertion during structured long-toss programs. Purpose: To determine whether decreased effort correlates with decreased throwing metrics, whether metrics decrease proportionally with reductions in perceived effort, and to quantify intrathrower variability. Study Design: Descriptive laboratory study. Methods: Sixty male high school and collegiate baseball pitchers participated in a structured throwing program. A motusBASEBALL sleeve was worn by all players, which measured elbow varus torque, arm velocity, arm slot, and shoulder rotation. Ball velocity was measured with a radar gun. Each pitcher threw 5 throws a distance of 120 ft with 3 efforts: maximum effort, 75% effort, and 50% effort. Throwing metrics were compared among the 3 levels of effort to see if each 25% decrease resulted in proportional decreases in elbow varus torque and ball velocity. Intrathrower variability was determined for each throwing metric at each degree of effort. Results: All throwing metrics decreased as players decreased their perceived effort ( P < .001). However, these observed decreases were much smaller in magnitude than the decreases in perceived effort. During the 75% effort throws, elbow varus torque was only reduced to 93% of maximum and velocity dropped to 86% of maximum. Similarly, for the 50% effort throws, elbow varus torque remained 87% of max effort torque, while velocity remained 78% of max. Intrathrower reliability was considered excellent for most metrics (intraclass correlation coefficient, >0.75). Conclusion: For every 25% decrease in perceived effort, elbow varus torque only decreased 7% and velocity only decreased 11%. Thus, when players throw at what they perceive to be reduced effort, their actual throwing metrics do not decrease at the same rate as their perceived exertion. Clinical Relevance: Measured effort decreased with decreasing perceived effort, but these were not proportional. This has significant implications for physical therapists, physicians, trainers, coaches, and athletes to understand and monitor elbow stress during the rehabilitation process.
Getting Hit by Pitch in Professional Baseball: Analysis of Injury Patterns, Risk Factors, Concussions, and Days Missed for Batters
Background: Although batters are frequently hit by pitch (HBP) in baseball, the effect of HBP injuries remains undefined in the literature. Purpose: To determine the effect of HBP injuries in terms of time out of play, injury patterns resulting in the greatest time out of play, and the value of protective gear such as helmets and elbow pads. Study Design: Descriptive laboratory study. Methods: Based on the Major League Baseball (MLB) Health and Injury Tracking System, all injuries to batters HBP during the 2011-2015 MLB and Minor League Baseball (MiLB) seasons were identified and analyzed. Video analysis was performed on all HBP events from the 2015 MLB season. Multivariate stepwise regression analysis was utilized to determine the predictive capacity of multiple variables (velocity, pitch type, location, etc) on injury status and severity. Results: A total of 2920 HBP injuries resulted in 24,624 days missed (DM) over the 5 seasons. MLB HBP injuries occurred at a rate of 1 per 2554 plate appearances (1 per 9780 pitches thrown). Mean DM per injury were 8.4 (11.7 for MLB vs 8.0 for MiLB, P < .001). Surgery was required for 3.1% of MLB injuries and 1.2% of MiLB injuries ( P = .005). The most common body regions injured were the hand/fingers (n = 638, 21.8%), head/face (n = 497, 17.0%), and elbow (n = 440, 15.7%), and there were 146 (5.0%) concussions. Injury rates and mean DM correlated with velocity in a near linear fashion. Players hit in the head/face (odds ratio, 28.7) or distal upper extremity (odds ratio, 6.4) were more likely to be injured than players HBP in other locations. Players with an unprotected elbow missed 1.7 more days (95% CI, –4.1 to 7.6) than those with an elbow protector ( P = .554) when injured after being HBP. Conclusion/Clinical Relevance: Although HBP injuries occur infrequently in the course of normal play, they collectively represent a significant source of time out of play. The most common body regions injured include the hands/fingers and head/face, and batters hit in these locations are significantly more likely to be injured. After contusions, concussions were the most common injury diagnosis.
Summative Report on Time Out of Play for Major and Minor League Baseball: An Analysis of 49,955 Injuries From 2011 Through 2016
Background: Recent epidemiologic reports have demonstrated rising injury rates in Major League Baseball (MLB) and Minor League Baseball (MiLB). Although several studies have recently been published on specific injuries, the majority of injuries have not yet been formally studied. Purpose: The purpose of this study is to (1) generate a summative analysis of all injuries that occur in MLB and MiLB, (2) identify the 50 most common injuries, and (3) generate focused reports and fact sheets on the characteristics of each of those diagnoses. Study Design: Case series; Level of evidence, 4. Methods: The MLB Health and Injury Tracking System was used to identify injuries occurring in MLB and MiLB players from 2011 to 2016. Injuries were defined as those that occurred during normal baseball activity and resulted in at least 1 day out of play. A multitude of player and injury characteristics were analyzed, and detailed reports of the 50 most commonly occurring injuries were generated. Results: A total of 49,955 injuries occurred during the study period; 45,123 were non–season ending, and they resulted in 722,176 days out of play. The mean (median) days missed per injury was 16 (6) days. Overall, 39.1% of all injuries occurred in pitchers. The upper extremity was involved in 39% of injuries, while 35% occurred in the hip/groin/lower extremity. Surgery was required in 6.5% of cases, and 9.7% of injuries were season ending. Hamstring strains were the most common injury (n = 3337), followed by rotator cuff strain/tear (n = 1874), paralumbar muscle strain (n = 1313), biceps tendinitis (n = 1264), oblique strain (n = 1249), and elbow ulnar collateral ligament injury (n = 1191). The diagnoses that were most likely to end a player’s season were elbow ulnar collateral ligament injury (60% season ending) and superior labrum anterior and posterior tear (50.9% season ending). Conclusion: Contrary to prior reports relying on disabled list data, the annual number of injuries in professional baseball remained steady from 2011 to 2016. Similar trends were noted for the annual number of days missed and mean days missed per injury. Although the mean days missed per injury was high (16), the median was much lower at 6 days.
Effect of Predraft Ulnar Collateral Ligament Reconstruction on Future Performance in Professional Baseball: A Matched Cohort Comparison
Background: In recent years, there has been a dramatic rise in the annual number of ulnar collateral ligament (UCL) reconstructions performed in amateur baseball pitchers. Accordingly, increasing numbers of players are entering professional baseball having already undergone the procedure; however, the effect of prior UCL reconstruction on future success remains unknown. Purpose: (1) To provide an epidemiologic report on baseball players who undergo UCL reconstruction before being selected in the Major League Baseball (MLB) Draft, (2) to define the outcomes in terms of statistical performance, and (3) to compare these results with those of matched controls (ie, non–UCL reconstruction). Study Design: Cohort study; Level of evidence, 3. Methods: The MLB Amateur Draft Database was queried to identify all drafted pitchers who underwent UCL reconstruction before being drafted. For each pitcher drafted from 2005 to 2014 with prior UCL reconstruction, 3 healthy controls with no history of elbow surgery were randomly identified for matched analysis. A number of demographic and performance comparisons were made between these groups. Results: A total of 345 pitchers met inclusion criteria. The annual number of pitchers undergoing predraft UCL reconstructions rose steadily from 2005 to 2016 ( P < .001). For matched control analysis, 252 pitchers with a UCL reconstruction and a minimum 2-year follow-up (drafted between 2005 and 2014) were matched to 756 controls (non–UCL reconstruction). As compared with the non–UCL reconstruction group, pitchers who underwent predraft UCL reconstruction reached the MLB level with greater frequency (20% vs 12%, P = .003), and their MLB statistical performances were similar for all measures. Compared with all other pitchers drafted during that period, players who had a predraft UCL reconstruction demonstrated an increased likelihood of reaching progressive levels of play (Full Season A, AA, and MLB) within a given time frame ( P < .05 for all). Conclusion: The number of UCL reconstructions performed in amateur baseball players before the draft increased year over year for the entire study period. Professional pitchers who underwent UCL reconstruction as amateurs appear to perform at least as well as, if not better than, matched controls without elbow surgery.
Epidemiology and Impact of Abdominal Oblique Injuries in Major and Minor League Baseball
Background: Oblique injuries are known to be a common cause of time out of play for professional baseball players, and prior work has suggested that injury rates may be on the rise in Major League Baseball (MLB). Purpose: To better understand the current incidence of oblique injuries, determine their impact based on time out of play, and to identify common injury patterns that may guide future injury prevention programs. Study Design: Descriptive epidemiological study. Methods: Using the MLB Health and Injury Tracking System, all oblique injuries that resulted in time out of play in MLB and Minor League Baseball (MiLB) during the 2011 to 2015 seasons were identified. Player demographics such as age, position/role, and handedness were included. Injury-specific factors analyzed included the following: date of injury, timing during season, days missed, mechanism, side, treatment, and reinjury status. Results: A total of 996 oblique injuries occurred in 259 (26%) MLB and 737 (74%) MiLB players. Although the injury rate was steady in MiLB, the MLB injury rate declined ( P = .037). A total of 22,064 days were missed at a mean rate of 4413 days per season and 22.2 days per injury. The majority of these occurred during batting (n = 455, 46%) or pitching (n = 348, 35%), with pitchers losing 5 days more per injury than batters ( P < .001). The leading side was injured in 77% of cases and took 5 days longer to recover from than trailing side injuries ( P = .009). Seventy-nine (7.9%) players received either a corticosteroid or platelet-rich plasma injection, and the mean recovery time was 11 days longer compared with those who did not receive an injection ( P < .001). Conclusion: Although the rate of abdominal oblique injuries is on the decline in MLB, this is not the case for MiLB, and these injuries continue to represent a significant source of time out of play in professional baseball. The vast majority of injuries occur on the lead side, and these injuries result in the greatest amount time out of play. The benefit of injections for the treatment of oblique injuries remains unknown.