Injury Rates in Major League Baseball During the 2020 COVID-19 Season

The COVID-19 lockdown as a model of detraining in division 1 college softball players

BACKGROUND

The COVID-19 pandemic interrupted the organized training of softball players, similar to the abrupt cessation of sports participation that can happen after an injury. Thus, the COVID-19 pandemic offers a unique model to study how sudden detraining influences softball players.

METHODS

We recruited a sample of convenience of National Collegiate Athletic Association Division 1 softball players. They participated in three data collections: pre-lockdown (Jan 2020, T1), post-lockdown (Sept 2020, T2), and before the 2021 season (Jan 2021, T3). Between T1 and T2, players received an at-home conditioning and throwing program, but compliance was not strictly monitored. Between T2-T3, players resumed formal fall training (team-organized workouts, on-field practice, and within-team scrimmage games). At each time point, we collected bilaterally: 1) shoulder internal rotation (IR) and external rotation (ER) range of motion (ROM); 2) shoulder IR and ER strength; 3) hip IR and ER ROM; and 4) hip abduction and extension strength. We used four independent (2 Sides × 3 Timepoints) MANOVA with repeated measures; we followed up significant MANOVA main effect of time with Sidak posthoc tests for pairwise comparisons between time points.

RESULTS

Fifteen players participated in this study. We found a significant MANOVA main effect of time for shoulder and hip ROM (p < 0.01). Between T1-T2, dominant shoulder ER ROM decreased 6.5°, dominant shoulder IR ROM increased 4.3°, and lead hip IR ROM increased 4.4°. Between T2-T3, dominant shoulder ER ROM increased 6.3° and trail hip ER ROM increased 5.9°. We found a significant MANOVA main effect of time for shoulder strength (p = 0.03) but not for hip strength (p = 0.18). Between T2-T3, non-dominant shoulder IR and ER increased 1.8 kg and 1.5 kg, respectively.

CONCLUSION

A sudden and prolonged cessation of organized training generated changes in shoulder and hip ROM but affected strength to a lesser extent. The loss of shoulder ER and increased lead hip IR ROM are maladaptive as they are associated with injury in overhead athletes. Resuming team-organized training and scrimmage reversed some (shoulder ER), but not all of these changes. Practitioners should monitor clinical variables regularly and be aware of potential changes due to unexpected and prolonged interruptions in training, such as when players suffer sports-related injuries.

Multivariate Analysis of Risk Factors for Injury and Surgical Interventions in Ankle and Knee Injuries in NBA Athletes

Objective

Lower extremity ankle and knee injuries occur at a high rate in the National Basketball Association (NBA) often requiring surgical intervention. This study aimed to identify surgical rates and risk factors for surgical intervention using multivariate analysis in ankle and knee injuries in NBA player.

Methods

Player demographics, performance metrics, advanced statistics, and injury characteristics were recorded using publicly available data. To standardize injury events over multiple years, injury events per 1000 athlete exposure events (AE, one player participating in one game) were calculated. Descriptive analysis and multivariate logistic regression were completed to find associations with surgical intervention in ankle and knee injuries.

Results

A total of 1153 ankle and knee injuries were included in the analysis with 73 (6.33%) lower extremity injuries treated with surgery. Knee injuries had a higher incidence of surgical intervention (0.23 AE) than ankle injuries (0.04 AE). The most frequent surgical knee injury was meniscus tear treated with meniscus repair (0.05 AE) and the most frequent ankle surgery was surgical debridement (0.01 AE) Multivariate logistic regression indicated lower extremity injuries that required surgery were associated with more minutes per game played (odds ratio [OR] 1.13; p = 0.02), a greater usage rate (OR 1.02 p < 0.001), the center position (OR 1.64; 95% [CI] 1.2-2.24; p = 0.002) and lower player efficiency rating (OR 0.96; 95% p < 0.001).

Conclusion

Knee surgery was significantly more frequent than ankle surgery despite similar injury rates per 1000 exposures. The center position had the greatest risk for lower extremity injury followed by minutes played while a higher player efficiency rating was protective against surgical intervention. Developing strategies to address these factors will help in the management and prevention of lower extremity injuries requiring surgical intervention.

'Benched' the effect of the COVID-19 lockdown on injury incidence in sub-elite football in Australia: a retrospective population study using injury insurance records

OBJECTIVES

The primary aim of this study was to compare injury rates pre- and post-COVID-19 lockdown in sub-elite football (soccer) players by analysing the full season and the first month of each season between 2018 and 2020. Secondary aims were to describe the incidence, location and type of injuries and to compare injuries by age group and sex.

DESIGN

Descriptive epidemiological study.

METHODS

A de-identified insurance database was retrospectively coded using the Orchard Sports Injury Classification System. Injury incidence per 1000 hours as well as incidence rate ratios (IRR) with confidence intervals were calculated.

RESULTS

No significant difference was found in the overall incidence rate in 2020 compared with the 2018 and 2019 seasons (IRR, 1.04 [95% CI, 0.96-1.13]; p = 0.294). However, overall injuries increased by 26% (IRR: 1.26 [95% CI 1.07-1.47]; p < 0.005) and joint sprains increased by 45% (IRR: 1.45 [95% CI 1.14-1.84]; p < 0.005) in the first month of 2020 compared with 2018-2019. Between 2018 and 2020, there were 4149 injury insurance claims, with anterior cruciate ligament (ACL) ruptures accounting for 19% of all injuries. When comparing sex, female players had significantly more ankle sprains whilst male players suffered more dental injuries.

CONCLUSIONS

This study adds to a growing body of evidence investigating injury rates post-COVID-19 lockdowns in sport. Sub-elite players appear to be at higher risk of joint injuries within the first month of training following a period of lockdown. Overall, stakeholders involved in sub-elite football should prioritise knee and ankle joint injury prevention.

Changes in injury type among NBA athletes in response to the COVID-19 pandemic

CONTEXT

The 2019-2020 NBA season was altered significantly by the COVID-19 pandemic with a midseason suspension of games, the NBA 'bubble' tournament, and a shortened offseason. Concerns were raised regarding player conditioning and the potential increased risk of injury due to the schedule changes. The purpose of this study was to determine the impact of the COVID-19 pandemic and associated schedule changes on NBA injuries. It was hypothesized that injury rates would be higher in the year following the pandemic and teams who participated in the bubble would have higher injury rates in the following season than non-bubble teams. Furthermore, the types of injuries would shift toward more severe injuries in the condensed 2019-20 season and the following 2020-21 season.

DESIGN

Retrospective Cohort Study.

METHODS

The NBA's public injury reports were queried to identify players listed on an injury report. Standardized injury events were calculated for four pre-COVID-19 seasons (2015-2019), the COVID-19 season (2019-2020), and the post-COVID-19 season (2020-2021). Injury characteristics including type and location were extracted for each year and differences within each period were calculated.

RESULTS

When excluding injury events related to COVID-19 health and safety protocols, the overall injury events per 1000 exposures were not significantly different between time periods of pre-COVID-19, COVID-19, and post-COVID-19 seasons; (p = 0.199), and no difference was found in the rates of teams who participated in the bubble. Injuries, including soreness and strains, significantly decreased while fracture injuries significantly increased in the COVID-19 year.

CONCLUSIONS

The COVID-19 pandemic led to an increased number of games missed, but no increase in injury rates when accounting for health and safety protocols. Additionally, bubble participation had no impact on injury rates. However, despite no changes in injury rates, the types of injuries changed with an increased proportion of severe injuries and decreased proportion of minor injuries.

Opposite effects of Covid-19 infection on pitchers and batters: a retrospective study on Chinese Professional Baseball League players

BACKGROUND

The influence of COVID-19 infection on elite athletes remains largely unknown, especially on baseball players. The goal of this study is to examine the actual performance of infected elite baseball players from the Chinese Professional Baseball League (CPBL) from a sabermetric point of view.

METHODS

This was a retrospective observational cohort study. CPBL players who were infected with COVID-19 from April 27th to May 31st, 2022, were eligible for this study. The performance of study participants before and after COVID-19 infection was compared, and statistics from the batters and pitchers were analyzed separately.

RESULTS

During the study interval, 56 players were infected with COVID-19, including 35 batters and 21 pitchers. After excluding injured players and players with inadequate playing opportunities, 23 batters and 12 pitchers were enrolled. For batters, there were no significant differences before and after COVID-19 infection. However, batters older than 28 years of age showed a decline in slugging percentage (0.372 vs. 0.292, P=0.049). Analysis of pitchers revealed significantly boosted fastball velocity after COVID-19 infection (142.10 km/h vs. 142.82 km/h, P=0.028) and improved strikeouts per nine innings (6.89 vs. 8.56, P=0.021).

CONCLUSIONS

COVID-19 might have a potential influence on professional baseball players. For batters, veteran players more than 28 years of age were more likely to be negatively affected by COVID-19, whereas the effect of COVID-19 on pitchers was generally positive, with significantly improved fastball velocity and K/9 numbers.

Changes in the incidence of stress reactions and fractures among intercollegiate athletes after the COVID-19 pandemic

PURPOSE

The purpose of this study was to characterize the impact of detraining due to the COVID-19 pandemic on incidence of bony injuries and stress fractures in collegiate athletes.

METHODS

A comprehensive collegiate athletic conference injury database was queried for all in-season, sport-related bony injuries (defined as all stress reactions and fractures) that occurred across all sports from January 2016 to June 2021. The bony injury rate per 1000 athlete exposure hours (AEH) was calculated and compared between the immediate post-hiatus season and historic rates from pre-hiatus seasons (2016-2019). Injury characteristics were also compared between the pre- and post-hiatus time periods.

RESULTS

A total of 868 bony injuries across 23 sports were identified. The sports with highest overall baseline bony injury rates in historic seasons were women's cross country (0.57 injuries per 1000 AEH) and men's cross country (0.32). Compared to historic pre-hiatus rates, female cross-country runners demonstrated a significantly lower bony injury incidence rate in the post-hiatus season (0.24 vs. 0.57, p = 0.016) while male swimming athletes demonstrated a statistically significant increase in bony injury rate (0.09 vs. 0.01, p = 0.015). The proportion of bony injuries attributed to repetitive trauma increased; while, the proportion of injuries attributed to running decreased between the pre- and post-hiatus seasons.

CONCLUSION

Across all sports, there was no consistent trend toward increased rates of bony injury in the immediate post-hiatus season. However, female cross-country runners demonstrated lower rates of bony injury in the post-hiatus season while male swimmers demonstrated higher rates. Furthermore, bony injuries in the post-hiatus season were more likely to be the result of repetitive trauma and less likely to be from running.

LEVEL OF EVIDENCE

Level III, retrospective, cross sectional study.

Injury Rates at an NCAA Division I Institution After the COVID-19 Lockdown: A Descriptive Epidemiological Study

Background

The coronavirus 2019 (COVID-19) pandemic led to frequent schedule changes, abbreviated seasons, and disrupted training at all levels of organized sports.

Purpose/Hypothesis

The purpose of this study was to investigate the epidemiology of sports-related injuries at a single National Collegiate Athletic Association (NCAA) Division I institution during the 2020 COVID lockdown season when compared with pre-COVID seasons. It was hypothesized that there would be an increase in the overall injury rate and an increase in the number of days missed because of injury during the 2020 season when compared with the previous seasons.

Study Design

Descriptive epidemiology study.

Methods

The injury surveillance database at a single NCAA Division I institution was queried for injuries that resulted in time loss (missed game or practice) for a student-athlete or for injuries that persisted >3 days. Injuries were categorized by anatomic area. Days unavailable because of injury were recorded as total days that a student-athlete was listed as "out of activity." Injury incidence and days unavailable, per 1000 athlete-exposures (AEs), were calculated for 3 pre-COVID seasons (2017-2019) and the 2020 season. The authors calculated the injury rate ratio (IRR) and its associated 95% CI of the 2020 season in comparison with those for the pre-COVID seasons.

Results

Compared with the pre-COVID seasons, the total injury incidence increased by 10.5% in the 2020 season (68.45 vs 75.65 injuries/1000 AEs; IRR, 1.11 [95% CI, 1.08-1.13]). Total days unavailable decreased by 20.7% in the 2020 season (1374 vs 1089 days/1000 AEs; IRR, 0.79 [95% CI, 0.77-2.26]). Compared with women's teams, men's teams had a larger increase in total injury incidence (16.4% vs 6.5%) and larger decrease in days unavailable (23.7% vs 10.75%). There were no clear trends to changes in anatomic distribution of injuries, either by sport or between the sexes.

Conclusion

Compared with the pre-COVID seasons, the injury incidence was higher and the number of days missed because of injury lower among collegiate student-athletes at a single NCAA Division I school in the season immediately after the COVID-19 lockdown.

Association of Injury Rates Among Players in the National Football League With Playoff Qualification, Travel Distance, Game Timing, and the Addition of Another Game: Data From the 2017 to 2022 Seasons

Background

Injury incidence is higher in the National Football League (NFL) than in other collision sports. Although previous research has identified that scheduling variations, including overseas games and bye week timing, does not affect concussion risk, data are currently lacking regarding the effects of scheduling variation on season-long musculoskeletal injury incidence.

Purpose

To determine whether higher cumulative travel distance, overseas play, an early season bye week, and an expansion of the regular season is associated with higher injury rates in the NFL.

Study Design

Descriptive epidemiology study.

Methods

All 1275 injuries across 5 NFL seasons from 2017 to 2018 through 2021 to 2022 were reviewed retrospectively. Injury data and travel distances were extracted from publicly available sources, which were cross-referenced for validation. Injury rates were calculated per 1000 athletic-exposures (AEs). Cumulative team travel distances were compared statistically using a linear regression. Single factor analysis of variance was used to compare categorical variables.

Results

Travel distance did not significantly predict injury rates (P = .47), and there was no difference in injury rates between teams that played a game overseas versus teams that did not (19.3 injuries per 1000 AEs for both; P = .96). In addition, no difference was found in injury rates (F[109,2100[ = 0.704; P = .73) or players placed on the injured reserve list (F[99,778] = 1.70; P = .077) between various bye weeks (P = .73). Injury rates did not differ between the new 17-game regular season (18.4 per 1000 AEs) versus the previous four 16-game regular seasons (19.7 per 1000 AEs; P = .12). However, teams that did not qualify for the playoffs had a significantly higher injury rate (19.9 per 1000 AEs) as well as players on injured reserve (8.0 per 1000 AEs) than playoff-qualifying teams (18.4 and 6.8 per 1000 AEs, respectively; P < .05 for both).

Conclusion

Over 5 NFL seasons, cumulative travel distance, overseas play, bye week timing, and adding 1 regular season game were not associated with increased injury rates in NFL players. However, a lack of regular season success was associated with higher injury rates and more players on injured reserve.

Elbow Injuries Among MLB Pitchers Increased During Covid-19 Disrupted Season, But Not Other Baseball Injuries

Background

The 2020 Major League Baseball Season (MLB) demonstrated season disruptions due to the COVID-19 pandemic. Changes in training and seasonal time frames may be associated with higher rates of injury.

Purpose

To use publicly available data to compare injury rates during the 2015-2019 seasons, COVID-19 shortened season (2020), and the 2021 season stratified by body region and position (pitchers versus position players).

Study Design

A retrospective cohort study utilizing publicly available data.

Methods

MLB players who competed in 1+ seasons between 2015-2021 were included and stratified by position (pitcher, position player). Incidence rate (IR), reported by 1000 x Athlete-Game Exposures (AGEs), was calculated for each season, and stratified by position and body region. Poisson regressions were performed for all injuries and stratified by position to determine association between season and injury incidence. Subgroup analyses were performed on the elbow, groin/hip/thigh, shoulder.

Results

Four thousand, two hundred and seventy-four injuries and 796,502 AGEs across 15,152 players were documented. Overall IR was similar across seasons (2015-2019:5.39; 2020:5.85; 2021:5.04 per 1000 AGEs). IR remained high for the groin/hip/thigh for position players (2015-2019:1.7; 2020:2.0; 2021:1.7 per 1000 AGEs). There was no difference in injury rates between 2015-2019 and 2020 seasons [1.1 (0.9-1.2), p=0.310]. The 2020 season demonstrated a significant increase in elbow injuries [2.7 (1.8-4.0), p<0.001]; when stratified by position, this increase remained significant for pitchers [pitchers: 3.5 (2.1-5.9), p<0.001; position players: 1.8 (0.9-3.6), p=0.073]. No other differences were observed.

Conclusion

The groin/hip/thigh demonstrated the highest IR in 2020 among position players across all season time frames, indicating that continued injury mitigation for this region is necessary. When stratified by body region, elbow injury rates among pitchers demonstrated 3.5 times the rate of injury in 2020 compared to previous seasons, impacting injury burden for the most vulnerable body region among pitchers.

Level of Evidence

Level III.

A Cross-Sectional Study of the Impact of the COVID-19 Pandemic and Lockdown Orders on Injury Prevalence in National Collegiate Athletic Association (NCAA) Division I Athletes

Objective The purpose of this study was to analyze the effect of the coronavirus disease 2019 (COVID-19) on injury prevalence in National Collegiate Athletic Association (NCAA) varsity athletes following mandatory state-issued stay-at-home orders in March 2020. A secondary objective was to evaluate the relationship between COVID-19 infection and injury prevalence. Methods The respondents were recruited during pre-participation evaluations held at a Division I university in California in the summer of 2021, as well as via emails shared by athletic trainers at the institution. Data was collected using the Qualtrics Survey Platform (Qualtrics, Provo, UT). For all questions regarding the effects of the COVID-19 pandemic, the participants were asked to compare March 2020-March 2021 ("post-pandemic") to March 2019-March 2020 ("pre-pandemic"). Injury was defined as a physical complaint or condition sustained by an athlete during participation in training or competition that resulted in at least one missed day of practice or competition. The study participants were also asked to disclose their history of laboratory-confirmed COVID-19 infection. Results One hundred forty-six respondents completed the survey, with a 72.3% response rate. Of the respondents, 33.6% (n=49) reported sustaining at least one injury in the year preceding the pandemic, whereas 45.2% (n=66) of respondents reported sustaining at least one injury within the first year of the pandemic, a 34.5% relative increase in injuries (RR=1.35; 95% CI=1.01, 1.80). There was no significant difference in the number of upper body (RR=1.64; 95% CI=0.8, 3.34; p=0.177) versus lower body (RR=1.31; 95% CI=0.94, 1.82; p=0.11) injuries before and after the pandemic onset. Thirty-two respondents reported a history of COVID-19 infection. The athletes who reported a prior COVID-19 diagnosis were no more likely than the athletes with no prior COVID-19 diagnosis to obtain an injury from March 2020 to February 2021 (p=0.85). Conclusion This study indicates that the COVID-19 pandemic and stay-at-home orders were associated with a greater risk of injury in this cohort of collegiate athletes. Interestingly, a history of laboratory-confirmed COVID-19 infection was not associated with increased risk of injury.

Injury rates in the National Football League during the 2020 COVID-19 season

OBJECTIVES

The National Football League (NFL) altered the 2020 season due to the COVID-19 pandemic, which resulted in canceled preseason games and a dynamic regular season schedule to accommodate for canceled games. The purpose of this study was to evaluate if the disrupted training and preseason schedule lead to increased injury rates as seen in other professional sports. We hypothesized that the overall injury rate would be higher in the 2020 season compared to the 2018-2019 seasons and that this increase will affect all body regions equally.

METHODS

Publicly released NFL weekly injury reports were queried to identify players listed as out or placed on the injured reserve for at least one game in the 2018-2020 seasons. Injuries were categorized into upper extremity, lower extremity, spine/core, head, illness, not injury related and undisclosed injuries. Incidents per 1000 athlete exposures were calculated for the prior two seasons (2018-2019) and for the 2020 season separately. Percentage of injuries occurring in each position was calculated separately for the pre-COVID-19 (2018 and 2019) and post-COVID-19 (2020) cohorts. Incidence rate ratios (IRR) and confidence intervals were used to compare injury rates in 2018-2019 versus 2020. The z-test for proportions was used to determine significant differences between injury incidences.

RESULTS

The overall incidence rate per 1000 athlete exposures in 2020 was not significantly different compared to pre-COVID-19 seasons (21.6 versus 23.1, IRR 0.94, 95% CI: 0.9-1.0 p > 0.999). The proportion of injuries by position did not change before and after COVID-19 either (p > 0.999). Out listings due to illness were significantly increased during the 2020 season (0.8 versus 0.3, IRR 2.8, 95% CI: 1.4-5.2, p = 0.004).

CONCLUSION

The incidence of NFL injuries did not significantly change in 2020. The distribution of injuries did not change with respect to position.

Effect of COVID-19 lockdown on injury incidence and burden in amateur rugby union

OBJECTIVES

To analyse match and training injury incidence rates and burden from pre-(2019) and post-COVID-19 (2021) seasons; To analyse injury related variables as mechanisms, type, body locations, severity and the differences of the most common injuries according to playing positions.

DESIGN

An observational study was performed according to the consensus statement on injury definitions and data collection from World Rugby. Injury variables were collected retrospectively for 2019 season and prospectively during 2021 season.

SETTING

Argentinian amateur rugby club.

PARTICIPANTS

Male (n = 110) senior amateur rugby players.

MAIN OUTCOME MEASURES

Match and training time loss injuries, time of exposures and injury related variables.

RESULTS

Training incidence rate during post-lockdown season (4.2/1000 player-training-hours) was significantly higher (p < 0.001) than the pre-lockdown season (0.9/1000 player match hours). Post-lockdown hamstring strain injury (HSI) and concussions match incidence rates were significantly (p < 0.001; p < 0.05 respectively) higher in comparison with 2019 season. Regarding playing positions, backs showed a significantly increase (p < 0.05) in HSI match incidence rate post lockdown.

CONCLUSIONS

After the COVID-19 lockdown, training incidence rate was significantly higher than previous season (2019), showing the impact of the lockdown restrictions. Coaches and medical staff must consider that players probably need more lead-in time for conditioning and more monitoring after periods of no rugby.

Effects of COVID-19 Sport Suspension on Injury Rates in Elite Athletes: A Critically Appraised Topic

Clinical Scenario: With the enforcement of COVID-19 lockdown restrictions, sports teams worldwide were required to make drastic adjustments to their training regimen. This prolonged sport suspension resulted in a significant decrease in off-season and preseason training periods. Clinical Question: Are professional athletes who experienced a sport suspension during the COVID-19 pandemic at a higher risk of injury once they return to competition compared with pre-COVID-19 seasons? Summary of Key Findings: The literature was searched for articles examining the effects of COVID-19 sport suspension on athletic injury rates in elite athletes. A total of 240 articles were retrieved, and after exclusion criteria and removal of duplicates, four retrospective cohort studies remained. An increase in injury rates across studies after their sport suspension compared with pre-COVID-19 seasons was found. Clinical Bottom Line: The extended suspension from physical activity increased the risk of injury as players returned to sport training post-COVID-19 restrictions. While these studies demonstrated the effects on elite-level athletes, prolonged sport suspension may impact different patient populations. Strength of Recommendation: Based on the Strength of Recommendation Taxonomy Scale, this critically appraised topic received a B grade for consistent but limited-quality patient-oriented evidence, with a low number of articles included.

COVID-19 modifications of offseason and preseason training for NFL athletes are associated with increased risk of regular season injuries

OBJECTIVES

COVID-19 altered National Football League (NFL) player and team training during the 2020 offseason. All preseason games were cancelled resulting in absence of game play before the first week of the regular season. Thus, concerns exist regarding injury susceptibility of players during regular season games. The purpose of this study was to evaluate and compare injury rates during the 2020 NFL season versus injury rates from the unaffected 2017-2019 seasons. We hypothesized there would be an increased injury rate and an increased rate of season ending injuries during the modified 2020 season.

METHODS

The NFL's public injury database was queried to identify players placed on the injury lists throughout the 2017-2020 seasons. All players listed as "out" and on the injured reserve due to physical injury were included in the data set. For further stratification, injury incidence was separated based on position. Time missed due to COVID-19 illness was not included. Injury rates were expressed as injuries per 1000 athlete exposures (AE).

RESULTS

Overall, 893 individual players missed games due to injury during the 2020 NFL regular season compared to an average of 743 over the 2017-2019 seasons. Defensive players at all positions had a statistically significant increase in injury incidence from an average of 7.54 to 10.20 injuries per 1000 AE. Defensive backs were most affected with a 46% increase in players injured. There was no statistically significant difference in season ending injuries for any position.

CONCLUSIONS

The COVID-19 stricken 2020 NFL regular season saw an increased rate and incidence of injuries. Specifically, defensive players had a higher incidence of injury overall with defensive backs experiencing the greatest increase in injury rates.

Regular-Season Injury Rates in the National Football League After an Attenuated Preseason Due to COVID-19

BACKGROUND

The preseason is a crucial time period for professional athletes to prepare for the upcoming season. However, due to the coronavirus 2019 (COVID-19) pandemic, the 2020 National Football League (NFL) preseason was canceled. As the regular season progressed, an increased number of injuries became apparent.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare injury rates between the 2019 and 2020 NFL regular seasons after the canceled 2020 preseason. It was hypothesized that injury rates in the 2020 season would be the same or higher compared with 2019.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A public database of all 32 NFL teams was used to examine the movement of all players to injured reserve status as well as every player who missed a regular-season game due to injury for both the 2019 and the 2020 NFL regular seasons. Data collection consisted of tallying the total number of reported musculoskeletal injuries for each team. Comparisons of injury rates between the 2 seasons were made using a Wilcoxon signed-rank statistical analysis.

RESULTS

The total number of musculoskeletal injuries was 632 for the 2019 regular season and 765 for the 2020 regular season (P = .0324). Compared with 2019, statistically significant increases in injury rates in 2020 were seen for calf or Achilles tendon strain (17 vs 39; P = .009), groin injury (25 vs 46; P = .018), and anterior cruciate ligament tear (14 vs 29; P = .016). There were several other increased trends in soft tissue injury rates in the 2020 season (eg, hamstring injury [87 vs 114; P = .085]); however, these did not reach statistical significance.

CONCLUSION

This study showed a significant increase in total injuries during the 2020 COVID-19-affected NFL regular season compared with 2019. Several major soft tissue injuries reached statistical significance in their increase from 2019 to 2020 after the cancellation of the 2020 preseason due to COVID-19. These findings suggest that organized team preseason training and conditioning could have an effect on the prevention of sport-related injury at the highest level.

A Plague of Their Own: Injury Incidence Remains Elevated in the 2021 Major League Baseball Season Compared to Pre-COVID-19 Seasons

Background

Significant increases in injuries were observed in the 2020 Major League Baseball (MLB) season; these were attributed to an increased acute to chronic workload due to the interrupted preseason and compressed season during the coronavirus disease of 2019 (COVID-19) pandemic. In 2021, the MLB resumed its regular schedule.

Hypothesis/Purpose

The purpose of this study was to determine the injury incidence and epidemiology of the 2021 MLB season compared to the injury incidence in the 2020 season and pre-COVID-19 seasons. The hypothesis was that, with the return to normal preseason training, injury incidence in 2021 would return to pre-COVID-19 rates. Additionally, it was hypothesized that injury list (IL) placements at midseason 2021 would be decreased relative to 2020 due to the uninterrupted preseason yet increased at full season 2021 due to increased overall workload from 2020.

Study Design

Descriptive epidemiology study.

Methods

The MLB transactions database was searched for players placed on the IL between 2018 and 2021. Injuries were categorized by body part and player position. Incidence per 1000 athlete-exposures was calculated for the pre-COVID-19 (2018-2019), 2020, and 2021 seasons. The z test for proportions was used to determine significant differences between injury incidences.

Results

The injury incidence rate by midseason 2021 (9.32) compared to 2020 (8.66) was not significantly different (p=0.234). At full season 2021, injury incidence rate (8.69) was significantly higher than pre-COVID-19 seasons (5.13, p<0.001), but not 2020 (p=0.952). When comparing full season 2021 to 2020, increased foot/ankle (0.50 vs 0.14, respectively, p<0.001) and miscellaneous (1.92 vs 0.68, respectively, p<0.001) injuries were observed.

Conclusion

The overall injury incidence in 2021 was significantly higher than pre-COVID-19 seasons, and no significant difference was observed between both mid- and full season 2021 and 2020, refuting the hypotheses. This signifies that injury incidence remained elevated in the 2021 season despite resumption of preseason training and a regular season.

Level of Evidence

3.

Impact of Sudden Rule Changes on Player Injuries and Performance: Insights from Australian Football

This study investigated the effects of reduced quarter time due to COVID-19 pandemic rule changes, on running performance and injuries in Australian Football. Microsensor data for eight matches performed by the same 17 players were compared between the 2019 (standard) and 2020 (COVID-19) seasons using linear and generalised mixed models. Injury rates were assessed in 34 players across the full 2019 season, and 32 players across the full 2020 season. The total distance (ES = 1.28 [0.55 to 2.02]), high-speed (>18 km/h) (ES = 0.44 [-0.24 to 1.12]) and very highspeed (>24 km/h) (ES = 0.27 [-0.41 to 0.94]) distances, PlayerLoad™ (ES = 0.96 [0.25 to 1.67]), high-intensity efforts (ES = 0.48 [-0.20 to 1.16]), and accelerations (ES = 0.33 [-0.34 to 1.01]) were smaller (p ≤ 0.01) for the 2020 than the 2019 season. Expressed relative to playing time, distance (ES=-0.38 [-1.06 to 0.30]), PlayerLoad™ (ES = -0.27 [-0.94 to 0.41]), and acceleration efforts (ES = -0.50 [-1.18 to 0.18]) were greater (p < 0.05) for the 2020 than the 2019 season. No significant differences in maximum ball-in-play periods nor the difference between the 1^st and 4^th quarters were evident. Injury rates remained similar between 2019 (3.36 per game) and 2020 (3.55 per game). However, the proportion of injuries that led to lost time (missed games) was greater for the 2020 (38%) than 2019 season (24%). The changes in the rules had a profound impact on player performance and increased the likelihood of time loss injuries.

Injury Incidence Increases after COVID-19 Infection: A Case Study with a Male Professional Football Team

Background: The SARS-CoV-2 virus disease has caused numerous changes in sports routines in the last two years, showing the influence on an increase in sports injuries. The aim of this study was to prospectively analyze the incidence and characteristics of injuries in male professional football players diagnosed with COVID-19 when they return to play after recovering from this illness. Methods: Injury characteristics of professional male football players were recorded for the 2020−2021 season following the international consensus statement from the International Olympic Committee (IOC). SARS-CoV-2 infection in the football players was certified by PCR analysis. Injury epidemiology was compared in players infected by the SARS-CoV-2 virus before and after being diagnosed with COVID-19. Results: 14 players (53.8%) were diagnosed with COVID-19 during 2020−2021 season and 12 (46.2%) were not infected (controls). Only three (21.4%) had suffered an injury before being diagnosed with COVID-19. Eleven players (78.6%) had injuries after being diagnosed with COVID-19 (p < 0.001). Among the players diagnosed with COVID-19, injury incidence increased on their return to play after the infection (3.8 to 12.4 injuries/1000 h of exposure, p < 0.001). Additionally, injury incidence during training (10.6 vs. 5.1 injuries/1000 h of exposure, p < 0.001) and matches (56.3 vs. 17.6 injuries/1000 h of exposure, p < 0.001) was ~two-fold higher on return to play after COVID-19 compared to controls (33.4 vs. 17.6 injuries/1000 h of exposure, respectively, p < 0.001). Conclusions: Injury incidence in professional football players who had been infected by the SARS-CoV-2 virus significantly increased compared to the injury rates that these same players had prior to the illness. Additionally, the injury incidence was higher when compared to players who were not infected by the SARS-CoV-2 virus during the season, especially during matches.

Effect of COVID-19 on Injury Rates and Timing in the National Football League

Background:

The coronavirus 2019 (COVID-19) pandemic resulted in the cancellation of the 2020 National Football League (NFL) preseason and a decreased preseason roster size. The effect of this disruption on athlete injury rates is unknown.

Purpose/Hypothesis:

The purpose was to quantify the rates of anterior cruciate ligament (ACL), Achilles tendon, and hamstring tendon injuries in NFL players before and after the COVID-19 pandemic. We hypothesized that injury rates in the 2020 season would be higher than those seen prepandemic.

Study Design:

Descriptive epidemiology study. Level of evidence, 4.

Methods:

An online search using publicly available data was carried out to identify all NFL players who sustained an ACL, Achilles tendon, or hamstring tendon injury between April 1, 2017, and March 31, 2021. Data collected included player characteristics as well as career and season of injury workloads.

Results:

The number of Achilles tendon (27 vs 20; P = .024) and hamstring tendon (186 vs 149; P < .001) injuries, respectively, in the 2020 NFL season were significantly higher than the average of the 2017 to 2019 seasons. However, the number of ACL injuries sustained remained constant (43 vs 46; P = .175). More than half (52.9%) of ACL injuries in the 2017 to 2019 seasons occurred in the preseason, while most of the injuries (34.9%) in the 2020 season occurred in weeks 1 to 4. There was no player characteristic or career workload variable collected that was significantly different for players who sustained an ACL, Achilles tendon, or hamstring tendon injury in the 2020 NFL season compared with the 2017 to 2019 seasons.

Conclusion:

In the 2020 NFL season, the number of Achilles tendon and hamstring tendon injuries rose while the number of ACL injuries remained constant compared with the 2017 to 2019 seasons. Injuries that occurred during the first 4 games of the 2020 NFL season were consistent, with higher rates of injuries seen in the preseason in previous years.

Lifestyle Changes and Baseball Activity among Youth Baseball Players before and during the First COVID-19 Pandemic in Japan

This cross-sectional study aimed to clarify the changes in lifestyle and baseball activity before and during the COVID-19 pandemic among youth baseball players. Participants were 99 youth baseball players (ages 9.6 ± 1.5 years, height 137.8 ± 9.4 cm, weight 35.3 ± 12.4 kg) in Japan. They completed an online survey between April 6 and 20, 2021, on their demographic characteristics, lifestyle (recreational screen, sleep, and study times), and baseball activity (frequency of team practice time and voluntary exercise-related baseball) at two-time points: before the pandemic (before March 2020) and during the state of emergency declared in Japan (from April to May 2020). The changes in outcomes between the two-time points were evaluated for significance. Recreational screen time and sleeping time during the state of emergency were significantly increased compared to those before the pandemic (p < 0.001). The frequency of team practice time on weekends during the state of emergency was significantly reduced, and voluntary exercise-related baseball was significantly increased compared to that before the pandemic (p < 0.01). We found that the COVID-19 pandemic changed behaviors concerning activities and exercise among youth baseball players and recommended that such behavioral changes be carefully monitored.

COVID-19 and Youth Sports: What Are the Risks of Getting Back on the Field Too Quickly?

The widespread shutdown in response to the coronavirus disease 2019 (COVID-19) pandemic, although varied across state and county levels, has undoubtedly impacted everyone to some degree. Within the pediatric population, the closure of schools and organized youth athletic programs has resulted in a unique situation that has made athletes physically deconditioned and at risk for injury. As sports and competition gradually restart, there are considerable risks to the skeletally immature athlete. The anatomic and physiologic changes that occur to bone and cartilage during growth make the young athlete particularly susceptible to both acute and overuse injuries. In the context of the pandemic, deconditioning, obesity, lack of variety, and the resultant mental health burden pose unique challenges in ensuring that young athletes safely return to the field. This review aims to identify risk factors for sport-related injuries and to outline strategies for minimizing these injuries as pediatric patients return-to-play after COVID-19. [Pediatr Ann. 2021;50(11):e465-e469.].