Resting Heart Rate Variability Among Professional Baseball Starting Pitchers.

Cornell, DJ, Paxson, JL, Caplinger, RA, Seligman, JR, Davis, NA, and Ebersole, KT. Resting heart rate variability among professional baseball starting pitchers. J Strength Cond Res 31(3): 575-581, 2017-The purpose of this study was to examine the changes in resting heart rate variability (HRV) across a 5-day pitching rotation schedule among professional baseball starting pitchers. The HRV data were collected daily among 8 Single-A level professional baseball starting pitchers (mean ± SD, age = 21.9 ± 1.3 years; height = 185.4 ± 3.6 cm; weight = 85.2 ± 7.5 kg) throughout the entire baseball season with the participant quietly lying supine for 10 minutes. The HRV was quantified by calculating the natural log of the square root of the mean sum of the squared differences (lnRMSSD) during the middle 5 minutes of each R-R series data file. A split-plot repeated-measures analysis of variance was used to examine the influence of pitching rotation day on resting lnRMSSD. A statistically significant main effect of rotation day was identified (F4,706 = 3.139, p = 0.029). Follow-up pairwise analyses indicated that resting lnRMSSD on day 2 was significantly (p ≤ 0.05) lower than all other rotation days. In addition, a statistically significant main effect of pitcher was also identified (F7,706 = 83.388, p < 0.001). These results suggest that professional baseball starting pitchers display altered autonomic nervous system function 1 day after completing a normally scheduled start, as day 2 resting HRV was significantly lower than all other rotation days. In addition, the season average resting lnRMSSD varied among participants, implying that single-subject analysis of resting measures of HRV may be more appropriate when monitoring cumulative workload among this cohort population of athletes.

In-Game Heart Rate Responses Among Professional Baseball Starting Pitchers.

Cornell, DJ, Paxson, JL, Caplinger, RA, Seligman, JR, Davis, NA, Flees, RJ, and Ebersole, KT. In-game heart rate responses among professional baseball starting pitchers. J Strength Cond Res 31(1): 24-29, 2017-The purpose of the current study was to characterize the in-game heart rate (HR) responses of baseball pitching. In-game HR was recorded from 16 professional baseball starting pitchers (mean ± SD, age = 22.1 ± 1.3 years; height = 187.9 ± 4.4 cm; weight = 90.5 ± 9.5 kg) for a total of 682 innings (home = 381, away = 301). All analyzed HR data were then normalized to each pitcher's age-predicted maximal HR (%HRmax). The group mean ± SD in-game %HRmax among all pitchers was 84.8 ± 3.9%, suggesting that baseball pitching is predominantly an anaerobic task. A split-plot mixed-model repeated measures analysis of variance identified a significant interaction effect between inning and game location (p = 0.042). Follow-up simple effects indicated that the in-game %HRmax was significantly different across innings, but only during home starts (p < 0.001). Specifically, pairwise analyses indicated that the in-game %HRmax during home starts were significantly (p ≤ 0.05) higher in the first and second innings than in all other innings. In addition, follow-up simple effects indicated that the in-game %HRmax was significantly (p = 0.017) higher during home starts than away starts in the first inning (87.3 ± 3.6% vs. 85.8 vs. 3.8%, respectively). Thus, it is possible that inning-dependent psychological factors may have contributed to the observed changes in in-game physiological intensity across innings and that these factors are specific to game location. Consequently, strength and conditioning practitioners should prescribe high-intensity exercises when developing conditioning programs for professional baseball starting pitchers.

Effect of education and language on baseline concussion screening tests in professional baseball players.

OBJECTIVE: The purpose of the present study was to investigate the possible effects of sociocultural influences, specifically pertaining to language and education, on baseline neuropsychological concussion testing as obtained via immediate postconcussion assessment and cognitive testing (ImPACT) of players from a professional baseball team. DESIGN: A retrospective chart review. SETTING: Baseline testing of a professional baseball organization. PARTICIPANTS: Four hundred five professional baseball players. INDEPENDENT VARIABLES: Age, languages spoken, hometown country location (United States/Canada vs overseas), and years of education. MAIN OUTCOME MEASURES: The 5 ImPACT composite scores (verbal memory, visual memory, visual motor speed, reaction time, impulse control) and ImPACT total symptom score from the initial baseline testing. RESULTS: The result of t tests revealed significant differences (P < 0.05) when comparing native English to native Spanish speakers in many scores. Even when corrected for education, the significant differences (P < 0.05) remained in some scores. CONCLUSIONS: Sociocultural differences may result in differences in computer-based neuropsychological testing scores.

Correlation of Joint Space Widening on Valgus Stress Magnetic Resonance Imaging With Level of Play and Innings Pitched in Professional Pitchers.

Background: Previous studies have described various techniques and confirmed the clinical utility of valgus stress radiography and stress ultrasound in overhead athletes. The addition of valgus stress and a high-resolution anatomic assessment of the elbow with magnetic resonance imaging (MRI) in the active throwing position (flexed elbow valgus external rotation [FEVER] view) can add valuable diagnostic or prognostic information in throwing athletes. Purpose/Hypothesis: The purpose of this study was to evaluate findings on MRI and subsequent performance in professional throwing athletes. It was hypothesized that joint space widening in the FEVER view would be predictive of performance and the risk of subsequent injuries. Study Design: Cross-sectional study; Level of evidence, 3. Methods: All pitchers on 2 Major League Baseball teams who consented to participate during their preseason screening in 2019 and 2020 underwent standard and FEVER MRI, and performance data from the following season were recorded, including injuries, mean throwing velocity, number of innings pitched, strikeout percentage, walk percentage, weighted on-base average, and level of play reached (not signed, minor league, or major league). Categorical variables were compared using the Fisher exact test or chi-square test, and continuous variables were compared using the Kruskal-Wallis test, as appropriate. Ordered logistic regression was used to determine the independent factors predicting performance. Results: A total of 91 players underwent preseason imaging, and all players had subsequent performance data available. Multivariate analysis revealed that when controlling for age, mean velocity, history of injuries, presence of symptoms, and history of ulnar collateral ligament reconstruction, increased absolute joint space widening was predictive of a lower level of play (ß = -0.63; P = .042). Univariate analysis demonstrated a significant correlation between relative joint space widening and level of play reached (ß = -0.54; P = .034). Relative joint space widening remained a significant predictor of level of play (ß = -0.87; P = .012) on multivariate analysis. Multivariate analysis also showed that both absolute joint space widening (ß = -13.50; P = .012) and relative joint space widening (ß = -13.60; P = .026) were predictive of the number of innings pitched in the subsequent season. Conclusion: The present study demonstrates that findings on MRI with valgus stress correlated with the level of play reached and number of innings pitched in professional throwing athletes.

Reliability of scapular classification in examination of professional baseball players.

BACKGROUND: Clinically evaluating the scapulothoracic joint is challenging. To identify scapular dyskinesis, clinicians typically observe scapular motion and congruence during self-directed upper extremity movements. However, it is unclear whether this method is reliable. QUESTIONS/PURPOSES: We therefore determined the interrater reliability of a scapular classification system in the examination of professional baseball players. METHODS: Seventy-one healthy uninjured professional baseball players between the ages of 18 and 32 years volunteered to participate. We used a digital video camera to film five repetitions of scapular plane elevation while holding a 2-pound weight. Four examiners then independently classified the motions on video into one of four types. Interrater reliability analysis using the kappa (k) statistic was performed for: (1) classifying each scapula into one of the four types; (2) classifying each scapula as being abnormal (Types I-III) or normal (Type IV); and (3) classifying both scapula as both being symmetric (both normal or both abnormal) or asymmetric (one normal, one abnormal). RESULTS: We found low reliability for all analyses. In classifying each scapula as one of the four types, reliability was k = 0.245 for the left limb and k = 0.186 for the right limb. When considering the dichotomous classifications (abnormal versus normal), reliability was k = 0.264 for left and k = 0.157 for right. For bilateral symmetry/asymmetric, reliability was k = 0.084. CONCLUSION: We found low reliability of visual observation and classification of scapular movement. CLINICAL RELEVANCE: Current evaluation strategies for evaluating subtle scapular abnormalities are limited. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Mild traumatic brain injury in major and Minor League Baseball players.

BACKGROUND: 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. PURPOSE: 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. STUDY DESIGN: Descriptive epidemiologic study. METHODS: 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. RESULTS: 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. CONCLUSION: 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.