Concussions impair balance, visual acuity, and reaction time--all of which are required for high-level batting performance--but the effects of concussion on batting performance have not been reported. The authors examined this relationship between concussion and batting performance among Major League Baseball (MLB) players.
Batting performance among concussed MLB players will be worse upon return to play than batting performance among players missing time for noninjury reasons.
Cohort study; Level of evidence, 3.
The authors identified MLB players who sustained a concussion between 2007 and 2013 through league disabled-list records and a Baseball Prospectus database. For a comparison group, they identified players who went on paternity or bereavement leave during the same period. Using repeated-measures generalized linear models, the authors compared 7 batting metrics between the 2 groups for the 2 weeks upon return, as well as 4 to 6 weeks after return, controlling for pre-leave batting metrics, number of days missed, and position.
The authors identified 66 concussions and 68 episodes of bereavement/paternity leave to include in the analysis. In the 2 weeks after return, batting average (.235 vs .266), on-base percentage (.294 vs .326), slugging percentage (.361 vs .423), and on-base plus slugging (.650 vs .749) were significantly lower among concussed players relative to the bereavement/paternity leave players (time×group interaction, P<.05). In weeks 4 to 6 after leave, these metrics were slightly lower in concussed players but not statistically significantly so.
Although concussed players may be asymptomatic upon return to play, the residual effects of concussion on the skills required for batting may still be present. Further work is needed to clarify the mechanism through which batting performance after concussion is adversely affected and to identify better measures to use for return-to-play decisions.
Shoulder injury in baseball pitchers is a very common problem and has been linked to an imbalance in rotator cuff strength. Recently, the use of functional shoulder strength ratios has become more popular because they more closely resemble the actions of the shoulder during the throwing motion.
To investigate the link between preseason shoulder rotator cuff functional strength ratios and the development of shoulder pain and injury.
Prospective research design.
University human performance laboratory.
Fifteen collegiate baseball pitchers participated in this study. At the end of the baseball season, six (19.5 ± 1.8 years, 73.6 ± 2.8 inches, 198.7 ± 19.1 lbs) developed shoulder injury and were placed in the injured group, and nine (21.0 ± 1.7 years, 73.1 ± 2.3 inches, 207.9 ± 28.1 lbs) did not develop injury and were placed in the noninjured group.
Isokinetic peak torque was collected concentrically and eccentrically for both shoulder internal rotation (IR) and external rotation (ER) at 60°·s–1, 180°·s–1, and 300°·s–1.
Main outcome Measure:
The following functional ratios were calculated from the peak torque measures: concentric ER: concentric IR; eccentric ER: eccentric IR; concentric ER: eccentric IR (cocking phase); and eccentric ER: concentric IR (acceleration phase). Analysis was conducted using an analysis of variance comparing the injured and noninjured groups. A secondary analysis was conducted using an analyses of variance on the concentric and eccentric peak torque for shoulder IR and ER between groups.
The acceleration phase functional shoulder ratio was significantly higher (p= .019) in the injured group and a concentric IR peak torque (p= .003) was significantly lower in the injured group compared with the noninjured group.
Increased acceleration phase ratios and decreased concentric IR peak torque may be linked to the development of shoulder injury during a baseball season.
Abnormal scapular kinematics during throwing motion in baseball players with shoulder disorders has not yet been clarified, although altered scapular position has been suggested to be associated with shoulder disorder.
To determine if the shoulders of baseball players with throwing disorders demonstrate abnormal scapular kinematics during the simulated arm-cocking phase of throwing activity.
Eleven baseball players (age 21.1 ± 1.2 y) with a unilateral shoulder disorder volunteered to participate, including 9 players at the college level and 2 at the adult level. The mean playing experience was 12.1 ± 2.7 y.
MAIN OUTCOME MEASURES:
Scapular upward/downward rotation, anteroposterior tilting, and external/internal rotation during simulated arm-cocking motion were analyzed using a 3-to-2-dimensional registration technique.
Scapular external rotation in the throwing shoulder was significantly smaller by 2.0-6.0° than that of the contralateral shoulder. There were no detectable differences in scapular upward/downward rotation or anteroposterior tilting between the throwing and contralateral shoulders.
Compared with that in the contralateral shoulder, scapular external rotation was smaller in the throwing shoulder, which would increase glenohumeral horizontal abduction during the arm-cocking phase and be related to the throwing-shoulder disorder.
The purpose of this study was to examine the relationship between dynamic hip rotational range of motion and upper extremity kinematics during baseball pitching. Thirty-one youth baseball pitchers (10.87 ± 0.92 years; 150.03 ± 5.48 cm; 44.83 ± 8.04 kg) participated. A strong correlation was found between stance hip rotation and scapular upward rotation at maximum shoulder external rotation (r = 0.531, P = 0.002) and at ball release (r = 0.536, P = 0.002). No statistically significant correlations were found between dynamic hip rotational range of motion and passive hip range of motion. Hip range of motion deficits can constrain pelvis rotation and limit energy generation in the lower extremities. Shoulder pathomechanics can then develop as greater responsibility is placed on the shoulder to generate the energy lost from the proximal segments, increasing risk of upper extremity injury. Additionally, it appears that passive seated measurements of hip range of motion may not accurately reflect the dynamic range of motion of the hips through the progression of the pitch cycle.
Medial ulnar collateral ligament (UCL) reconstruction is a common procedure performed on professional pitchers in Major League Baseball (MLB). Although a great deal is known about primary reconstruction, much less is known about revision reconstruction.
The purpose of this study was to evaluate statistical performance, return to play, and career longevity in MLB pitchers after revision UCL surgery, with the hypothesis that pitching performance and career longevity will decline after revision surgery.
Cohort study; Level of evidence, 3.
A total of 33 MLB pitchers who underwent revision UCL reconstruction surgery (UCL-R group) were identified and compared with 33 age- and position-matched controls (CTL group). Return to play, total years played, and statistical performance were evaluated and compared with controls.
After revision surgery, 65.5% of UCL-R pitchers returned to the MLB level. On average, the UCL-R pitchers played 0.8 years less in the majors (P<.01) than did the control pitchers. The UCL-R pitchers who returned to the MLB level had a similar earned run average (UCL-R: 4.88, CTL: 4.76, P=.82) and walks/hits per innings pitched (UCL-R: 1.58, CTL: 1.44, P=.22) compared with the control pitchers. There were significant declines, however, in terms of innings pitched (UCL-R: 36.95, CTL: 75.00, P<.01), walks per 9 innings (UCL-R: 4.75, CTL: 3.49, P<.01), and wins (UCL-R: 1.88, CTL: 4.10, P<.01) as well as nonsignificant declines in wins above replacement (UCL-R: 0.25, CTL: 0.62, P=.06) and runs above replacement (UCL-R: 3.26, CTL: 6.91, P=.07).
MLB pitchers who undergo UCL-R have a low rate of return to MLB play and have shortened careers after return. Pitchers who returned to the MLB level maintained performance in several statistics such as earned run average and walks/hits per innings pitched; however, pitchers returned with a significantly decreased workload.
Overuse injury in youth baseball players is increasing in prevalence, and these injuries have been correlated to pitching mechanics and pitch counts/types. Prior studies regarding arm pain in these athletes have focused simply on presence or absence of pain during the season rather than on detailed factors related to arm pain with respect to frequency, severity, and associated performance and psychosocial effect.
The goal of this study was to investigate frequency, quality, and effect of arm pain in healthy youth baseball players. The hypothesis was that arm pain will affect a majority of healthy baseball players and will be associated with adverse psychosocial effects.
Descriptive epidemiological study.
A novel survey focusing on arm pain in youth baseball players was developed for the purpose of this study. Survey questions were formulated by a consortium of trainers, clinicians, and coaches. Surveys were administered to healthy youth baseball players throughout the states of New Jersey and New York.
A total of 203 healthy players completed the survey; 23% of players (n=47) reported a prior overuse injury. Only 26% and 20% of players reported that their arm never hurt when throwing or the day after throwing, respectively; 30% of players reported that arm pain at least sometimes caused them to have less fun playing; and 46% of players reported at least once being encouraged to keep playing despite having arm pain. Pitchers were more likely to report arm pain while throwing and the day after throwing and to indicate that arm pain held them back from being a better player (all P<.05). Those with prior overuse injury were more likely to have arm pain while throwing, to have arm fatigue during a game or practice, and to be encouraged to keep playing despite having pain (all P<.05).
A majority of healthy (actively competing) youth baseball players report at least some baseline arm pain and fatigue, and many players suffer adverse psychosocial effects from this pain.
The purpose of this study was to better understand how lower body kinematics relate to peak glenohumeral compressive force and develop a regression model accounting for variability in peak glenohumeral compressive force. Data were collected for 34 pitchers. Average peak glenohumeral compressive force was 1.72% ± 33% body weight (1334.9 N ± 257.5). Correlation coefficients revealed 5 kinematic variables correlated to peak glenohumeral compressive force (P< .01,?= .025). Regression models indicated 78.5% of the variance in peak glenohumeral compressive force (R2= .785,P< .01) was explained by stride length, lateral pelvis flexion at maximum external rotation, and axial pelvis rotation velocity at release. These results indicate peak glenohumeral compressive force increases with a combination of decreased stride length, increased pelvic tilt at maximum external rotation toward the throwing arm side, and increased pelvis axial rotation velocity at release. Thus, it may be possible to decrease peak glenohumeral compressive force by optimizing the movements of the lower body while pitching. Focus should be on both training and conditioning the lower extremity in an effort to increase stride length, increase pelvis tilt toward the glove hand side at maximum external rotation, and decrease pelvis axial rotation at release.
Although mild traumatic brain injury (MTBI) is not as common in professional baseball as in collision sports, it does occur and frequently results in significant loss of time away from the sport. To date, no study has investigated MTBI among an entire cohort of professional baseball players.
To investigate MTBIs in major and minor league baseball players to determine the most common mechanisms of injury, activity at time of injury, position, level of play, and time lost, as well as ultimately inform prevention efforts. A secondary objective was to document the association between MTBI and return to play using several different measures.
Descriptive epidemiologic study.
Data were captured from a newly implemented league-wide injury surveillance system that records injuries among all professional baseball players as entered by certified athletic trainers and physicians. The MTBIs were identified with respect to level of play, activity, field location, and mechanism of injury. Time loss was assessed by 3 measures of return to play, and MTBI game rates were reported as injuries per 1000 athlete-exposures. Data were combined over the 2011-2012 seasons for analysis, and results were presented separately for minor and major league players. Chi-square tests were used to test the hypothesis of equal proportions between the various categories of MTBI injury characteristics.
There were 41 reported MTBIs in the major leagues and 266 in the minor leagues over the 2-year period under study. The overall MTBI game rate across both major and minor league ball clubs was 0.42 per 1000 athlete-exposures. The median time lost was 9 days. Mild traumatic brain injury accounted for 1% of all injuries resulting in time lost from play. For MTBIs that occurred while fielding, catchers were significantly overrepresented. No differences were noted among the 3 measures of time lost.
Mild traumatic brain injury is an important problem in professional baseball players, especially for catchers. This study provides a foundation for future inquiry to reduce the incidence of MTBI in those positions at greatest risk and to provide a baseline as rules and equipment evolve.