The Burden of Back and Neck Strains and Sprains in Professional Baseball Players

STUDY DESIGN

A retrospective case series study.

OBJECTIVE

To analyze the epidemiology of diagnoses of back and neck strains and sprains among Major League (MLB) and Minor League (MiLB) Baseball players.

BACKGROUND

Baseball players perform unique sets of repetitive movements that may predispose to neck and back strains and sprains. Data are lacking concerning the epidemiology of these diagnoses in this population.

MATERIALS AND METHODS

De-identified data on neck/back strains and sprains were collected from all MLB and MiLB teams from 2011 to 2016 using the MLB-commissioned Health and Injury Tracking System database. Diagnosis rates of conditions related to cervical, thoracic, and lumbar musculature and their impact on days missed due to injury, player participation, and season or career-ending status were assessed. Injury rates were reported as injuries per 1000 athlete exposures (AEs).

RESULTS

There were 3447 cases of neck/back strains and sprains in professional baseball players from 2011 to 2016. Seven hundred twenty-one of these occurred in MLB versus 2726 in MiLB. Of injuries 136 were season-ending (26 in MLB, 110 in MiLB); 22 were career-ending (2 in MLB, 20 in MiLB). The total days missed were 39,118 (8838 from MLB and 30,280 from MiLB). Excluding season or career-ending injuries, the mean days missed were 11.8 (12.7 and 11.6 in MLB and MiLB, respectively). The median days missed were 4 (3 and 5 in MLB and MiLB, respectively). Combining MLB and MiLB, the pitcher injury rate was 1.893 per 1000 AEs versus 0.743 per 1000 Aes for other position players (P < 0.0001).

CONCLUSION

There was a high incidence of neck/back strains and sprains in MLB and MiLB players, with nearly 40,000 aggregate days missed in our 6-year study period. The median days missed were lower than the mean days missed, indicating rightward outliers. Pitchers had over double the rates of injuries compared with other position players.

LEVEL OF EVIDENCE

Level III.

Developing a National-Scale Exposure Index for Combined Environmental Hazards and Social Stressors and Applications to the Environmental Influences on Child Health Outcomes (ECHO) Cohort

Tools for assessing multiple exposures across several domains (e.g., physical, chemical, and social) are of growing importance in social and environmental epidemiology because of their value in uncovering disparities and their impact on health outcomes. Here we describe work done within the Environmental influences on Child Health Outcomes (ECHO)-wide Cohort Study to build a combined exposure index. Our index considered both environmental hazards and social stressors simultaneously with national coverage for a 10-year period. Our goal was to build this index and demonstrate its utility for assessing differences in exposure for pregnancies enrolled in the ECHO-wide Cohort Study. Our unitless combined exposure index, which collapses census-tract level data into a single relative measure of exposure ranging from 0-1 (where higher values indicate higher exposure to hazards), includes indicators for major air pollutants and air toxics, features of the built environment, traffic exposures, and social determinants of health (e.g., lower educational attainment) drawn from existing data sources. We observed temporal and geographic variations in index values, with exposures being highest among participants living in the West and Northeast regions. Pregnant people who identified as Black or Hispanic (of any race) were at higher risk of living in a "high" exposure census tract (defined as an index value above 0.5) relative to those who identified as White or non-Hispanic. Index values were also higher for pregnant people with lower educational attainment. Several recommendations follow from our work, including that environmental and social stressor datasets with higher spatial and temporal resolutions are needed to ensure index-based tools fully capture the total environmental context.

Malaria in Refugee Children Resettled to a Holoendemic Area of Sub-Saharan Africa

BACKGROUND

Malaria is a leading cause of morbidity and mortality in refugee children in high-transmission parts of Africa. Characterizing the clinical features of malaria in refugees can inform approaches to reduce its burden.

METHODS

The study was conducted in a high-transmission region of northern Zambia hosting Congolese refugees. We analyzed surveillance data and hospital records of children with severe malaria from refugee and local sites using multivariable regression models and geospatial visualization.

RESULTS

Malaria prevalence in the refugee settlement was similar to the highest burden areas in the district, consistent with the local ecology and leading to frequent rapid diagnostic test stockouts. We identified 2197 children hospitalized for severe malaria during the refugee crisis in 2017 and 2018. Refugee children referred from a refugee transit center (n = 63) experienced similar in-hospital mortality to local children and presented with less advanced infection. However, refugee children from a permanent refugee settlement (n = 110) had more than double the mortality of local children (P < .001), had lower referral rates, and presented more frequently with advanced infection and malnutrition. Distance from the hospital was an important mediator of the association between refugee status and mortality but did not account for all of the increased risk.

CONCLUSIONS

Malaria outcomes were more favorable in refugee children referred from a highly outfitted refugee transit center than those referred later from a permanent refugee settlement. Refugee children experienced higher in-hospital malaria mortality due in part to delayed presentation and higher rates of malnutrition. Interventions tailored to the refugee context are required to ensure capacity for rapid diagnosis and referral to reduce malaria mortality.

Associations between combined exposure to environmental hazards and social stressors at the neighborhood level and individual perinatal outcomes in the ECHO-wide cohort

Limited studies examine how prenatal environmental and social exposures jointly impact perinatal health. Here we investigated relationships between a neighborhood-level combined exposure (CE) index assessed during pregnancy and perinatal outcomes, including birthweight, gestational age, and preterm birth. Across all participants, higher CE index scores were associated with small decreases in birthweight and gestational age. We also observed effect modification by race; infants born to Black pregnant people had a greater risk of preterm birth for higher CE values compared to White infants. Overall, our results suggest that neighborhood social and environmental exposures have a small but measurable joint effect on neonatal indicators of health.

Epidemiology of Spine-Related Neurologic Injuries in Professional Baseball Players

STUDY DESIGN

A retrospective case series study.

OBJECTIVE

To analyze the epidemiology of diagnoses of degenerative cervical and lumbar spinal conditions among Major League Baseball (MLB) and Minor League Baseball (MiLB) players.

SUMMARY OF BACKGROUND DATA

Repetitive high-energy forces in professional baseball players may predispose them to degenerative cervical and lumbar spinal conditions. There is a lack of data concerning the epidemiology of these injuries in professional baseball.

METHODS

Deidentified data on spine injuries were collected from all MLB and MiLB teams from 2011 to 2016 from the MLB-commissioned Health and Injury Tracking System database. Rates of diagnoses of common degenerative spinal conditions as well as their impact on days missed due to injury, necessitation of surgery, and player participation and career-ending status were assessed. Injury rates were reported as injuries per 1000 athlete-exposures in concordance with prior studies.

RESULTS

Over 2011 to 2016, 4246 days of play were missed due to 172 spine-related injuries. 73.3% were related to the lumbar spine and 26.7% to the cervical spine. There were similar rates of surgery required for these injuries (18.3% of lumbar injuries vs. 13.0% of cervical injuries, P = 0.2164). Mean age of players with cervical injuries was higher compared with the lumbar group (27.5 vs. 25.4, P = 0.0119). Average number of days missed due to lumbar injuries was significantly higher than those due to cervical injuries (34.1 vs. 21.6 d, P = 0.0468). Spine injury rates for pitchers were significantly higher than those of other position players (0.086 per 1000 athlete-exposures vs. 0.037, P < 0.0001).

CONCLUSION

Neurologic diagnoses relating to the cervical and lumbar spine lead to substantial disability among MLB and MiLB players as well as days missed from play. Pitchers have over double the rates of injury compared with other position players. Lumbar conditions were associated with significantly higher numbers of days missed from play.Level of Evidence: 4.

Effect of Weather and Game Factors on Injury Rates in Professional Baseball Players

BACKGROUND

Injury rates in baseball players of all ages are increasing. Identifying modifiable risk factors is paramount to implementing injury prevention programs.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the influence of weather (temperature, humidity, atmospheric pressure, and heat index) and game factors (start time, duration, single vs doubleheader) on injury rates in professional baseball players. We hypothesized that colder temperatures would be associated with significantly more injuries per game.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a retrospective database study. Two data sets were combined: 1 containing all injuries in Major and Minor League Baseball between 2011 and 2017 and 1 containing all games played in Major and Minor League Baseball during the same period to determine the number of injuries per game. Temperature, humidity, atmospheric pressure, and heat index were determined for each game using the data from the US Environmental Protection Agency. Additional game variables included the level of play, the turf type (natural vs artificial grass), the stadium type (open vs dome vs retractable), the game start time, the game duration, and whether the game was a doubleheader. Then, a multivariate analysis was conducted to determine which factors were associated with the number of injuries per game.

RESULTS

In total, our analysis included 33,587 injuries and 76,747 games. A total of 25,776 (33.6%) games contained an injury, and 41% of injuries occurred as multiples per game, with up to 9 injuries per game. The multivariate analysis identified significant associations between game duration and injuries per game (P < .001; effect size, 0.013) and the level of play and injuries per game (P < .001; effect size, 0.011). There were significant associations between the venue type (P < .001), the game start time (P < .001), humidity (P < .001), the turf type (P = .016), and barometric pressure (P = .031); however, the effect size for each was <0.001, suggesting that these factors are clinically unimportant. Our overall model produced an R² of 0.04, indicating that these variables only predicted 4% of the variance in injury risk.

CONCLUSION

In professional baseball, the weather is not associated with injury risk; however, game duration may contribute to injury risk.

The Lyme and Tickborne Disease Dashboard: A map-based resource to promote public health awareness and research collaboration

With the incidence of Lyme and other tickborne diseases on the rise in the US and globally, there is a critical need for data-driven tools that communicate the magnitude of this problem and help guide public health responses. We present the Johns Hopkins Lyme and Tickborne Disease Dashboard (https://www.hopkinslymetracker.org/), a new tool that harnesses the power of geography to raise awareness and fuel research and scientific collaboration. The dashboard is unique in applying a geographic lens to tickborne diseases, aiming not only to become a global tracker of tickborne diseases but also to contextualize their complicated geography with a comprehensive set of maps and spatial data sets representing a One Health approach. We share our experience designing and implementing the dashboard, describe the main features, and discuss current limitations and future directions.

Examining Batting Performance After a Sports-Related Concussion Among Major League Baseball Position Players

BACKGROUND

An ongoing challenge in sports-related concussion (SRC) is determining full recovery. This study examines performance metrics in baseball after an SRC and provides a template for assessment of return-to-performance parameters.

PURPOSE

To determine whether batting performance returns to baseline after an SRC.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Participants were all Major League Baseball (MLB) position players with confirmed SRCs that occurred during the 2011-2015 seasons. A retrospective review and assessment of performance metrics before and after injury were conducted as defined relative to the number of plate appearances (PAs) to yield reliable performance statistics. Seven batting metrics were considered as outcomes in longitudinal regressions: batting average, on-base percentage, slugging percentage, on-base plus slugging, bases on balls, strikeouts, and home runs. Metrics were calculated for each player 60, 30, and 14 days before their SRCs, as well as for the 14, 30, and 60 days after returning to play. Other variables controlled for included defensive position, player age at the time of SRC, number of days missed, mechanism of injury, whether the player completed a rehabilitation stint, and year in which the mild traumatic brain injury (MTBI) occurred (2011-2015).

RESULTS

A total of 77 MTBI case events occurred in MLB position players over 5 seasons. These injuries resulted in a mean 11.4 days lost to injury. For all performance metrics using 60 or 30 days before MTBI as baseline, no statistically significant differences were found in batting performance. In total, 63 events met PA criteria before injury. Varying the PA cutoff thresholds to be more inclusive or more restrictive yielded similar regression results. For the 48 events that met PA criteria before and after injury, most performance metrics showed no significant performance change after MTBI and, in some events, a slight though mostly nonsignificant performance improvement after MTBI.

CONCLUSIONS

MLB position players who are medically cleared to return to play after an SRC perform at the same offensive performance levels as their preinjury statistics when an adequate number of PAs is used to compare performance before and after injury.

A syndromic surveillance tool to detect anomalous clusters of COVID-19 symptoms in the United States

Coronavirus SARS-COV-2 infections continue to spread across the world, yet effective large-scale disease detection and prediction remain limited. COVID Control: A Johns Hopkins University Study, is a novel syndromic surveillance approach, which collects body temperature and COVID-like illness (CLI) symptoms across the US using a smartphone app and applies spatio-temporal clustering techniques and cross-correlation analysis to create maps of abnormal symptomatology incidence that are made publicly available. The results of the cross-correlation analysis identify optimal temporal lags between symptoms and a range of COVID-19 outcomes, with new taste/smell loss showing the highest correlations. We also identified temporal clusters of change in taste/smell entries and confirmed COVID-19 incidence in Baltimore City and County. Further, we utilized an extended simulated dataset to showcase our analytics in Maryland. The resulting clusters can serve as indicators of emerging COVID-19 outbreaks, and support syndromic surveillance as an early warning system for disease prevention and control.

A syndromic surveillance tool to detect anomalous clusters of COVID-19 symptoms in the United States

Coronavirus SARS-COV-2 infections continue to spread across the world, yet effective large-scale disease detection and prediction remain limited. COVID Control: A Johns Hopkins University Study, is a novel syndromic surveillance approach, which collects body temperature and COVID-like illness (CLI) symptoms across the US using a smartphone app and applies spatio-temporal clustering techniques and cross-correlation analysis to create maps of abnormal symptomatology incidence that are made publicly available. The results of the cross-correlation analysis identify optimal temporal lags between symptoms and a range of COVID-19 outcomes, with new taste/smell loss showing the highest correlations. We also identified temporal clusters of change in taste/smell entries and confirmed COVID-19 incidence in Baltimore City and County. Further, we utilized an extended simulated dataset to showcase our analytics in Maryland. The resulting clusters can serve as indicators of emerging COVID-19 outbreaks, and support syndromic surveillance as an early warning system for disease prevention and control.

A Spatiotemporal Analysis of Organ-Specific Lupus Flares in Relation to Atmospheric Variables and Fine Particulate Matter Pollution

OBJECTIVE

To identify potential clusters of systemic lupus erythematosus (SLE) organ-specific flares and their relationship to fine particulate matter pollution (PM2.5), temperature, ozone concentration, resultant wind, relative humidity, and barometric pressure in the Hopkins Lupus Cohort, using spatiotemporal cluster analysis.

METHODS

A total of 1,628 patients who fulfilled the Systemic Lupus International Collaborating Clinics classification criteria for SLE and who had a home address recorded were included in the analysis. Disease activity was assessed using the Lupus Activity Index. Assessment of rash, joint involvement, serositis, and neurologic, pulmonary, renal, and hematologic activity was quantified on a 0-3 visual analog scale (VAS). An organ-specific flare was defined as an increase in VAS of ≥1 point compared to the previous visit. Spatiotemporal clusters were detected using SaTScan software. Regression models were used for cluster adjustment and included individual, county-level, and environmental variables.

RESULTS

Significant clusters unadjusted for environmental variables were identified for joint flares (P < 0.05; n = 3), rash flares (P < 0.05; n = 4), hematologic flares (P < 0.05; n = 3), neurologic flares (P < 0.05; n = 2), renal flares (P < 0.001; n = 4), serositis (P < 0.001; n = 2), and pulmonary flares (P < 0.001; n = 2). The majority of the clusters identified changed in significance, temporal extent, or spatial extent after adjustment for environmental variables.

CONCLUSION

We describe the first spatiotemporal clusters of lupus organ-specific flares. Seasonal, as well as multi-year, cluster patterns were identified, differing in extent and location for the various organ-specific flare types. Further studies focusing on each individual organ-specific flare are needed to better understand the driving forces behind these observed changes.

Adjusted, non-Euclidean cluster detection of Vibrio parahaemolyticus in the Chesapeake Bay, USA

Vibrio parahaemolyticus (V. parahaemolyticus) is a naturallyoccurring bacterium found in estuaries, such as the Chesapeake Bay (USA), that can cause vibriosis, a food - and waterborne illness, in humans. Tracking the spatial and temporal distribution of V. parahaemolyticus in the Chesapeake Bay, which varies in part due to water temperature, salinity, and other environmental variables, can help identify areas and time periods of high risk. These observations can support interventions used to reduce the burden of vibriosis. Spatial and spatiotemporal clusters of high V. parahaemolyticus abundance were identified among surface water samples in the Chesapeake Bay between 2007 and 2010. While Euclidean distances between geographic points in spatial analyses are often used for cluster detection, non-Euclidean distances should be considered for cluster detection due to the complex nature of the Chesapeake Bay shoreline. Comparison of both methods consistently showed the non-Euclidean cluster detection providing unique and more reasonable clusters than the Euclidean approach. Residuals from univariate and multivariate models were used to identify how clusters changed after controlling for environmental variables. Most clusters tended to decrease in space, time, or significance after adjustment, suggesting these covariates contributed to the original formation of the clusters and as such are useful observation tools for vibriosis risk managers. Clusters that remained after adjustment suggest areas for further study and intervention. These findings reinforce the importance of using non-Euclidean distances when tracking the spatiotemporal variation of V. parahaemolyticus as well as the benefits of cluster detection methods for V. parahaemolyticus risk management in estuaries.

Epitaxial Growth of Magnetic Nickel Nanodots by Pulsed Laser Deposition

Epitaxial nickel magnetic nanodots were obtained by pulsed laser deposition (PLD) technique on Si (100) substrate using epitaxial TiN film as the template. Characterization methods include: high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM) Z-contrast imaging, selected area electron diffraction (SAD), and X-ray diffraction (XRD) techniques. The results showed that as long as no coalescence between neighboring dots occurred, the dots are all single crystal. The predominant orientation relationship observed is Ni (100) // TiN (100) // Si (100), the so-called “cube-on-cube” orientation relationship. Other rotational orientation relationships, where the nickel crystal rotates an angle with respect to TiN (011) directions, were also observed. The dots are in faceted island shapes, bounded by (111) and (001) facets. The actual size of dots varies from a few nanometers to tens of nanometers, depending on the deposition time and temperature. The shape of a certain dot was found to be closely related to its epitaxial orientation. Effects of deposition temperature and template crystalline quality were studied. It was found that deposition temperature in a certain range does not have much influence on the epitaxial orientation of dots, while the crystalline quality of titanium nitride (the underlying template) is primarily responsible for the orientation variation. At the optimum condition, samples with a large fraction of cube-on-cube orientated nickel dots could be obtained in a rather wide temperature range (up to 250 °C), as evidenced by the strong reflections from both SAD and XRD. Samples containing more than one layer of nickel and titanium nitride matrix were also studied. The results showed that the degree of orientation perfection could be greatly improved by decreasing the size of dots.

Growth Of ZnO/MgZnO Superlattice On Sapphire

The optical and structural properties of ZnO/ MgZnO superlattices were investigated by transmission electron microscope, transmission measurement and photoluminescence. The uncoupled wells ranged in thickness from ∼30 Å to 75 Å. Modulation of the Mg content was observed in Z-contrast TEM indicating the alloy composition was periodic. The density of stacking faults in the superlattice was extremely high, however the photoluminescence in the narrowest well case was blue shifted, and substantially brighter than comparable bulk layers of ZnO and MgZnO indicating that the emission was enhanced. Excitonic features were observed in the optical absorption spectra and also revealed that diffusion of Mg from the barrier layers into the well was occurring.

Optical and Structural Characteristics Of Gold Nanocrystallites Embedded in a Dielectric Matrix

We have fabricated Gold (Au) crystallites in amorphous alumina matrix by pulsed laser deposition. The characterization of these multilayer sequences was performed by high resolution transmission electron microscopy (HRTEM) and optical transmission measurements. TEM studies revealed the morphology and the microstructure of these composites. The optical transmission spectra showed characteristic surface plasma resonance of Au particles confined by the host dielectric matrix. These resonances fall in the visible spectral range. The importance of pulsed laser deposition in fabricating these composite films is discussed.

Growth of epitaxial ZnO films on Si(111)

Epitaxial ZnO films have been grown on Si(111) substrates by employing a AlN buffer layer during a pulsed laser-deposition process. The epitaxial structure of AlN on Si(111) substrate provides a template for ZnO growth. The resultant films are evaluated by transmission electron microscopy, x-ray diffraction, and electrical measurements. The results of x-ray diffraction and electron microscopy on these films clearly show the epitaxial growth of ZnO films with an orientational relationship of ZnO[0001]||Aln[0001]||Si[111] along the growth direction and ZnO[2 11 0]||AlN[2 11 0]||Si[0 11] along the in-plane direction. High electrical conductivity (103 S/m at 300 K) and a linear I-V characteristics make these epitaxial films ideal for microelectronic, optoelectronic, and transparent conducting oxide applications.

High-performance lithium-ion anodes using a hierarchical bottom-up approach

Si-based Li-ion battery anodes have recently received great attention, as they offer specific capacity an order of magnitude beyond that of conventional graphite. The applications of this transformative technology require synthesis routes capable of producing safe and easy-to-handle anode particles with low volume changes and stable performance during battery operation. Herein, we report a large-scale hierarchical bottom-up assembly route for the formation of Si on the nanoscale--containing rigid and robust spheres with irregular channels for rapid access of Li ions into the particle bulk. Large Si volume changes on Li insertion and extraction are accommodated by the particle's internal porosity. Reversible capacities over five times higher than that of the state-of-the-art anodes (1,950 mA h g(-1)) and stable performance are attained. The synthesis process is simple, low-cost, safe and broadly applicable, providing new avenues for the rational engineering of electrode materials with enhanced conductivity and power.