It's a Hard-Knock Life: Game Load, Fatigue, and Injury Risk in the National Basketball Association

The Utility of High-Intensity, Intermittent Exercise Protocols to Induce Fatigue for Screening Purposes in Jump-Landing Sports

Short-term fatigue protocols simulating sports participation are scarce and not well-documented in jump-landing sports. Therefore, this study investigated physiological and physical responses following high-intensity, intermittent exercise protocols (HIIPs) with a standardized level of subjective exhaustion (Borg ≥18/20) and a modified fixed version of five circuits (HIIP-5) for future inclusion in biomechanical screening protocols. Twenty male volleyball and basketball players participated in this study to complete the HIIP and the HIIP-5. Physiological and physical variables were assessed before and up to 30 min after cessation of both protocols. Regarding physiological variables, heart rate values increased (+104 bpm, p < 0.001) and remained elevated up to 30 min (+34 bpm, p < 0.001), and blood lactate levels increased (+17 mmol/l, p < 0.001) compared to baseline. Regarding physical variables, decreased jump height (-4 cm, p = 0.001-0.009) and quadriceps muscle strength (p = 0.001-0.050) were observed up to 30 min compared to baseline. The type of the fatigue protocol did not have an effect on the investigated variables (p > 0.05). To conclude, both the HIIP and the HIIP-5 seem valuable tools to induce acute and long-lasting responses, providing a sufficiently large time window of 30 min within which biomechanical markers of injury can be assessed under fatigued conditions in future risk factor screenings. In practice, the fatigue protocol can be terminated after only five circuits if athletes had not yet been stopped at that point due to exhaustion (Borg ≥18/20).

Editorial Commentary: Load Management Is Essential to Prevent Season-Ending Injuries in the National Basketball Association

Each season, National Basketball Association (NBA) athletes subject themselves to a physical season including a minimum of 82 games, intense travel, participation during holidays, innumerable training sessions, and for some, playoffs continuing into June. Intensity and fatigue may contribute to a high rate of injuries, and recent literature has suggested that primary risk factors for season-ending injuries are minutes played per game and later season games. Scheduled periods of rest, or load management, reduce the physiological load a player endures during a grueling season. Disadvantages of load management may include decrements in individual skill, team competitiveness, and financial issues, including disappointed fans. Thus, in 2023, the NBA instituted the Player Participation Policy (PPP) placing stipulations on load management by asking teams to balance player rest between home and away games and to refrain from long-term shutdowns of player participation for nonmedical reasons. From a medical standpoint, safeguarding athlete health is of paramount importance. Managing the workload of NBA players may have numerous player benefits and must be achieved while mitigating the disadvantages.

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.

Severe Acute Respiratory Syndrome Coronavirus 2 Did Not Substantially Impact Injury Patterns or Performance of Players in the National Basketball Association From 2016 to 2021

Purpose

To perform a descriptive epidemiologic analysis of National Basketball Association (NBA) injuries from 2016 to 2021, to evaluate the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease 2019, or COVID-19) on injury patterns and performance statistics, and to determine the effect of infection with SARS-CoV-2 on individual performance statistics.

Methods

Injury epidemiology in the NBA from the 2016 to 2021 seasons was collected using a comprehensive online search. Injuries and time missed were categorized by injury location and type. Player positions and timing of injury were recorded. Performance statistics were collected including traditional game statistics and Second Spectrum (speed, distance) statistics. Comparisons were made over seasons and comparing the pre-COVID-19 pandemic seasons to the pandemic era seasons. Players diagnosed with COVID-19 were analyzed for changes in performance in the short or long term.

Results

Of the 3,040 injuries captured, 1,880 (61.84%) were in the lower extremity. Guards (77.44%) and forwards (75.88%) had a greater proportion of soft-tissue injuries (P < .001) than centers. Guards had the highest proportion of groin (3.27%, P = .001) and hamstring (6.21%, P < .001) injuries. Despite minor differences on a per-season basis, there were no differences in injury patterns identified between pre-COVID-19 and COVID-19 eras. Of players diagnosed with COVID-19 during the NBA Bubble, there were no detriments in short- or long-term performance identified, including traditional game statistics and speed and distance traveled.

Conclusions

In the NBA seasons from 2016 to 2021, most injuries were to the lower extremity. The SARS-CoV-2 pandemic did not substantially impact injury patterns in the NBA, including locations of injury and type of injury (bony or soft tissue). Furthermore, infection with SARS-CoV-2 does not appear to have a significant impact on performance in basketball-specific or speed and distance measures.

Level of Evidence

Level IV, prognostic case series.

Characterization of Ankle Injuries and Associated Risk Factors in the National Basketball Association: Minutes Per Game and Usage Rate Associated With Time Loss

Background

Ankle injuries are more common in the National Basketball Association (NBA) compared with other professional sports.

Purpose/Hypothesis

The purpose of this study was to report the incidence and associated risk factors of ankle injuries in NBA athletes. It was hypothesized that factors associated with an increased physiologic burden, such as minutes per game (MPG), usage rate, and associated lower extremity injury, would be associated with increased ankle injury risk and time loss.

Study Design

Descriptive epidemiology study.

Methods

Ankle injury data from the 2015-2016 through 2020-2021 NBA seasons were evaluated. The truncated 2019-2020 season due to the COVID-19 pandemic was omitted. The primary outcome was the incidence of ankle injuries, reported per 1000 game-exposures (GEs). Secondary analysis was performed to identify risk factors for ankle injuries through bivariate analysis and multivariable logistic regression of player demographic characteristics, performance statistics, injury characteristics, and previous lower extremity injuries. Factors influencing the time loss after injury were assessed via a negative binomial regression analysis.

Results

A total of 554 ankle injuries (4.06 injuries per 1000 GEs) were sustained by NBA players over 5 NBA seasons, with sprain/strain the most common injury type (3.71 injuries per 1000 GEs). The majority of ankle injury events (55%) resulted in 2 to 10 game absences. The likelihood of sustaining an ankle injury was significantly associated with a greater number of games played (P = .029) and previous injury to the hip, hamstring, or quadriceps (P = .004). Increased length of absence due to ankle injury was associated with greater height (P = .019), MPG (P < .001), usage rate (P = .025), points per game (P = .011), and a prior history of foot (P = .003), ankle (P < .001), and knee injuries (P < .001).

Conclusion

The incidence of ankle injuries was 4.06 per 1000 GEs in professional basketball players. Games played and prior history of hip, hamstring, or quadriceps injuries were found to be risk factors for ankle injuries. Factors associated with physiologic burden such as MPG and usage rate were associated with an increased time loss after injury.

Does rest breed rust? An examination of DNP-Rest decisions and performance in the National Basketball Association regular and post-season

Within the National Basketball Association (NBA), players and teams maintain that having healthy players sit out some games during the regular season may help them be more productive during the post-season. This decision to not play in order to rest the player, aptly noted as a DNP-Rest decision on injury reports, is in line with team and player goals, and fits with a growing body of evidence in support of the power of rest for health and performance. However, these practices conflict with some goals of the league, which has a vested interest in having the top talent play to attract broadcasters, advertisers, live spectators, and thus, enhance viewership. The current study is among the first to test the theory that strategically resting healthy players during the regular season results in better performance, as indicated by Player Efficiency Rating (PER) and Win Shares, during the post-season. Utilizing data from the 2016–17 through the 2020–21 NBA seasons, there was not sufficient evidence to suggest that resting more games during the regular season results in better performance in the post-season. Findings from a nested case-control study of 184 players (92 cases; 92 controls) also showed no differences in the change in performance from regular to post-season between cases of players who received rest during the regular season and matched controls. Although the restorative effects of rest might be considerable in the short term, the current study provides additional evidence to suggest that the impact may not carry over into the post-season.

Associations of circadian change, travel distance, and their interaction with basketball performance: a retrospective analysis of 2014-2018 National Basketball Association data

This investigation aimed to clarify the influence of circadian change and travel distance on National Basketball Association (NBA) team performance using a dataset from the 2014-2018 seasons. Data from 9,840 games were acquired from an open-access source. Game point differential and team free-throw percentage served as outcome variables. Time zone change (TZΔ) captured raw circadian delay/advance based on travel for a game and adjusted TZΔ (AdjTZΔ) evolved TZΔ by allowing acclimation to a novel TZ. We also further categorized AdjTZΔ into AdjTZΔ_A, which assumed travel the day before each game and AdjTZΔ_B, which assumed teams spent as many days in their home city as possible. Travel distance for each game was calculated. Linear mixed-effects modeling estimated associations, with games nested within team and year. Adjusted associations accounted for differences in team ability, whether the game was home or away, and whether the game occurred on the second half of a back-to-back game sequence. Greater circadian misalignment, regardless of delay or advance, and increasing travel distance negatively influenced NBA game performance. Yet, results suggest that performance outcomes may be more influenced by travel distance than circadian misalignment. Moreover, circadian misalignment and travel distance interacted to significantly influence game point differential. Furthermore, differences in results across analyses were observed between AdjTZΔ_A and AdjTZΔ_B, which suggests that subtle differences in constructed travel schedules can have notable impact on NBA performance outcomes. Lastly, playing on the second half of a back-to-back sequence emerged as a robust predictor of performance disadvantage, which corroborates the existing literature and provides further support for NBA schedule changes purposed to enhance competitive equity by reducing the number of back-to-back games across a season. These findings can help guide NBA teams on key strategies for reducing travel-related disadvantages and inform schedule makers on critical factors to prioritize across future schedules to attenuate competitive inequity from travel. Furthermore, they can help direct teams towards scenarios that are best to target for load management purposes due to the cumulative disadvantage arising from travel-related factors, opponent quality, game location, and game sequence.

Using Artificial Intelligence-Enhanced Sensing and Wearable Technology in Sports Medicine and Performance Optimisation

Wearable technologies are small electronic and mobile devices with wireless communication capabilities that can be worn on the body as a part of devices, accessories or clothes. Sensors incorporated within wearable devices enable the collection of a broad spectrum of data that can be processed and analysed by artificial intelligence (AI) systems. In this narrative review, we performed a literature search of the MEDLINE, Embase and Scopus databases. We included any original studies that used sensors to collect data for a sporting event and subsequently used an AI-based system to process the data with diagnostic, treatment or monitoring intents. The included studies show the use of AI in various sports including basketball, baseball and motor racing to improve athletic performance. We classified the studies according to the stage of an event, including pre-event training to guide performance and predict the possibility of injuries; during events to optimise performance and inform strategies; and in diagnosing injuries after an event. Based on the included studies, AI techniques to process data from sensors can detect patterns in physiological variables as well as positional and kinematic data to inform how athletes can improve their performance. Although AI has promising applications in sports medicine, there are several challenges that can hinder their adoption. We have also identified avenues for future work that can provide solutions to overcome these challenges.

Effect of a Condensed NBA Season on Injury Risk: An Analysis of the 2020 Season and Player Safety

Background:

Health and safety concerns surrounding the coronavirus 2019 (COVID-19) pandemic led the National Basketball Association (NBA) to condense and accelerate the 2020 season. Although prior literature has suggested that inadequate rest may lead to an increased injury risk, the unique circumstances surrounding this season offer a unique opportunity to evaluate player safety in the setting of reduced interval rest.

Hypothesis:

We hypothesized that the condensed 2020 NBA season resulted in an increased overall injury risk as compared with the 2015 to 2018 seasons.

Study Design:

Descriptive epidemiology study.

Methods:

A publicly available database, Pro Sports Transactions, was queried for injuries that forced players to miss ≥1 game between the 2015 and 2020 seasons. Data from the 2019 season were omitted given the abrupt suspension of the league year. All injury incidences were calculated per 1000 game-exposures (GEs). The primary outcome was the overall injury proportion ratio (IPR) between the 2020 season and previous seasons. Secondary measures included injury incidences stratified by type, severity, age, position, and minutes per game.

Results:

A total of 4346 injuries occurred over a 5-season span among 2572 unique player-seasons. The overall incidence of injury during the 2020 season was 48.20 per 1000 GEs but decreased to 39.97 per 1000 GEs when excluding COVID-19. Despite this exclusion, the overall injury rate in 2020 remained significantly greater (IPR, 1.42 [95% CI, 1.32-1.52]) than that of the 2015 to 2018 seasons (28.20 per 1000 GEs). On closer evaluation, the most notable increases seen in the 2020 season occurred within minor injuries requiring only a 1-game absence (IPR, 1.53 [95% CI, 1.37-1.70]) and in players who were aged 25 to 29 years (IPR, 1.57 [95% CI, 1.40-2.63]), averaging ≥30.0 minutes per game (IPR, 1.67 [95% CI, 1.47-1.90]), and playing the point guard position (IPR, 1.67 [95% 1.44-1.95]).

Conclusion:

Players in the condensed 2020 NBA season had a significantly higher incidence of injuries when compared with the prior 4 seasons, even when excluding COVID-19–related absences. This rise is consistent with the other congested NBA seasons of 1998 and 2011. These findings suggest that condensing the NBA schedule is associated with an increased risk to player health and safety.

Sports Medicine and Artificial Intelligence: A Primer

Artificial intelligence (AI) represents the fourth industrial revolution and the next frontier in medicine poised to transform the field of orthopaedics and sports medicine, though widespread understanding of the fundamental principles and adoption of applications remain nascent. Recent research efforts into implementation of AI in the field of orthopaedic surgery and sports medicine have demonstrated great promise in predicting athlete injury risk, interpreting advanced imaging, evaluating patient-reported outcomes, reporting value-based metrics, and augmenting the patient experience. Not unlike the recent emphasis thrust upon physicians to understand the business of medicine, the future practice of sports medicine specialists will require a fundamental working knowledge of the strengths, limitations, and applications of AI-based tools. With appreciation, caution, and experience applying AI to sports medicine, the potential to automate tasks and improve data-driven insights may be realized to fundamentally improve patient care. In this Current Concepts review, we discuss the definitions, strengths, limitations, and applications of AI from the current literature as it relates to orthopaedic sports medicine.

Quantifying Training and Game Demands of a National Basketball Association Season

Purpose: There are currently no data describing combined practice and game load demands throughout a National Basketball Association (NBA) season. The primary objective of this study was to integrate external load data garnered from all on-court activity throughout an NBA season, according to different activity and player characteristics. Methods: Data from 14 professional male basketball players (mean ± SD; age, 27.3 ± 4.8 years; height, 201.0 ± 7.2 cm; body mass, 104.9 ± 10.6 kg) playing for the same club during the 2017-2018 NBA season were retrospectively analyzed. Game and training data were integrated to create a consolidated external load measure, which was termed integrated load. Players were categorized by years of NBA experience (1-2y, 3-5y, 6-9y, and 10 + y), position (frontcourt and backcourt), and playing rotation status (starter, rotation, and bench). Results: Total weekly duration was significantly different (p < 0.001) between years of NBA playing experience, with duration highest in 3-5 year players, compared with 6-9 (d = 0.46) and 10+ (d = 0.78) year players. Starters experienced the highest integrated load, compared with bench (d = 0.77) players. There were no significant differences in integrated load or duration between positions. Conclusion: This is the first study to describe the seasonal training loads of NBA players for an entire season and shows that a most training load is accumulated in non-game activities. This study highlights the need for integrated and unobtrusive training load monitoring, with engagement of all stakeholders to develop well-informed individualized training prescription to optimize preparation of NBA players.

Effects of Hypopressive Exercise on Posterior Back Chain Kinematics and Pulmonary Function in Professional Female Basketball Players

CONTEXT

Hypopressive exercise (HE) has been used as an alternative lumbo-pelvic injury prevention program and claimed to be a means of respiratory and flexibility improvement. However, the possible effects of HE on athletic populations and physical performance remain unclear.

OBJECTIVE

Examine the effects of a HE program on posterior back chain kinematics, thoracic mobility, pulmonary function, and lower lumbar pain in female basketball players over an 8-week training period.

DESIGN

Prospective (1) baseline, (2) midpoint (4 wk), and (3) after 8 weeks.

SETTING

Sports field.

PARTICIPANTS

A total of 17 professional female basketball players (mean age 20.7 y, SD: 3.50; body mass index, 21.71, SD: 1.69).

INTERVENTION

Participants performed 8 HE weekly sessions of 30 minutes.

MAIN OUTCOME MEASURES

Back chain kinematics was assessed with the sit and reach and finger to floor test, and back pain was assessed through numerical rating scale. Respiratory parameters were assessed by spirometry and through thoracic mobility.

RESULTS

The analysis of variance revealed significant differences between the 3 measurement periods for thoracic mobility (P > .01); forced expiratory volume in the first second (P < .05) while no statistical differences were found for the rest of spirometry outcomes. Significant differences were also revealed between baseline and after the intervention for the sit and reach test (P > .01), peak expiratory flow (P = .01), and forced expiratory volume in the first 25 seconds (P = .04). Also, significant differences between weeks were found in levels of lumbar pain (P = .003) and the finger to floor test (P = .002).

CONCLUSIONS

These preliminary findings suggest that a HE program can improve posterior back chain and chest wall kinematics as well as lower lumbar pain levels. However, no gains seem to be observed for the majority of pulmonary variables except for peak expiratory flow and forced expiratory volume in the first seconds.

In-Season Nutrition Strategies and Recovery Modalities to Enhance Recovery for Basketball Players: A Narrative Review

Basketball players face multiple challenges to in-season recovery. The purpose of this article is to review the literature on recovery modalities and nutritional strategies for basketball players and practical applications that can be incorporated throughout the season at various levels of competition. Sleep, protein, carbohydrate, and fluids should be the foundational components emphasized throughout the season for home and away games to promote recovery. Travel, whether by air or bus, poses nutritional and sleep challenges, therefore teams should be strategic about packing snacks and fluid options while on the road. Practitioners should also plan for meals at hotels and during air travel for their players. Basketball players should aim for a minimum of 8 h of sleep per night and be encouraged to get extra sleep during congested schedules since back-to back games, high workloads, and travel may negatively influence night-time sleep. Regular sleep monitoring, education, and feedback may aid in optimizing sleep in basketball players. In addition, incorporating consistent training times may be beneficial to reduce bed and wake time variability. Hydrotherapy, compression garments, and massage may also provide an effective recovery modality to incorporate post-competition. Future research, however, is warranted to understand the influence these modalities have on enhancing recovery in basketball players. Overall, a strategic well-rounded approach, encompassing both nutrition and recovery modality strategies, should be carefully considered and implemented with teams to support basketball players' recovery for training and competition throughout the season.

Impacts of travel distance and travel direction on back-to-back games in the National Basketball Association

STUDY OBJECTIVES

Travel fatigue and circadian disruptions are known factors that can hinder performance in professional athletes. The present study focused on travel distance and direction on back-to-back games over the 2013-2020 seasons in the National Basketball Association (NBA).

METHODS

The outcomes were based on winning percentage with additional covariates including the direction of travel (eastward or westward), the distance traveled (0-500 km; 501-1,000 km; 1,001-1,500 km; 1,501 km and more), team quality, and season. If a team played both games of a back-to-back sequence on the road, they were considered Away-Away; if a team played the first game of a back-to-back sequence at home they were considered Home-Away; if a team played the first game of a back-to-back sequence on the road they were considered Away-Home.

RESULTS

The sequence Away-Home significantly increases the likelihood of winning compared with the Away-Away and Home-Away sequences: 54.4% (95% confidence interval [CI], 54.4%-54.5%), 39.2% (95% CI, 37.2%-41.2%), and 36.8% (95% CI, 36.7%-36.8%), respectively. When teams travel back home, every additional 500 km reduces the likelihood of winning by approximately 4% (P = .038). Finally, after withdrawing the Away-Home sequence, traveling eastward significantly increases the chance of winning (P = .024) compared with westward travel but has no significant impact on the probability of winning compared with neutral time zone travel (P = .091).

CONCLUSIONS

The accumulation of travel fatigue and the chronic circadian desynchronization that occurs over the NBA season can acutely disturb sleep and recovery. It appears that tailored sleep and recovery strategies need to be dynamically developed throughout the season to overcome the different challenges of the NBA schedule.

CITATION

Charest J, Samuels CH, Bastien CH, Lawson D, Grandner MA. Impacts of travel distance and travel direction on back-to-back games in the National Basketball Association. J Clin Sleep Med. 2021;17(11):2269-2274.

Impact of Patellar Tendinopathy on Player Performance in the National Basketball Association

Background:

The extent to which patellar tendinopathy affects National Basketball Association (NBA) athletes has not been thoroughly elucidated.

Purpose:

To assess the impact patellar tendinopathy has on workload, player performance, and career longevity in NBA athletes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

NBA players diagnosed with patellar tendinopathy between the 2000-2001 and 2018-2019 seasons were identified through publicly available data. Characteristics, return to play (RTP), player statistics, and workload data were compiled. The season of diagnosis was set as the index year, and the statistical analysis compared post- versus preindex data acutely and in the long term, both within the injured cohort and with a matched healthy NBA control cohort.

Results:

A total of 46 NBA athletes were included in the tendinopathy group; all 46 players returned to the NBA after their diagnosis. Compared with controls, the tendinopathy cohort had longer careers (10.50 ± 4.32 vs 7.18 ± 5.28 seasons; P < .001) and played more seasons after return from injury (4.26 ± 2.46 vs 2.58 ± 3.07 seasons; P = .001). Risk factors for patellar tendinopathy included increased workload before injury (games started, 45.83 ± 28.67 vs 25.01 ± 29.77; P < .001) and time played during the season (1951.21 ± 702.09 vs 1153.54 ± 851.05 minutes; P < .001) and during games (28.71 ± 6.81 vs 19.88 ± 9.36 minutes per game; P < .001). Players with increased productivity as measured by player efficiency rating (PER) were more likely to develop patellar tendinopathy compared with healthy controls (15.65 ± 4.30 vs 12.76 ± 5.27; P = .003). When comparing metrics from 1 year preinjury, there was a decrease in games started at 1 year postinjury (−12.42 ± 32.38 starts; P = .028) and total time played (−461.53 ± 751.42 minutes; P = .001); however, PER at 1 and 3 years after injury was unaffected compared with corresponding preinjury statistics.

Conclusion:

NBA players with a higher PER and significantly more playing time were more likely to be diagnosed with patellar tendinopathy. Player performance was not affected by the diagnosis of patellar tendinopathy, and athletes were able to RTP without any impact on career longevity.

Return to play, performance, and value of National Basketball Association players following Achilles tendon rupture

Background: Achilles tendon ruptures are devastating injuries for National Basketball Association (NBA) players: prior studies have demonstrated decreased performance following return-to-play, but none have evaluated the effect of injury on rate-adjusted contextual statistics to assess the true change in performance. Additionally, there exists a paucity of data on the independent impact on defensive performance following return.Hypothesis: Compared to both control-matched peers and preoperative careers, we hypothesize that player production based on rate-adjusted contextual statistics will significantly decline following Achilles tendon rupture.Study design: Retrospective Cohort StudyMethods: Publicly available NBA injury data on Achilles tendon rupture were reviewed from the 1996 -1997 to the 2016-2017 seasons. Controls were matched based on height, position, age, and rate-adjusted statistics. Extracted data included Value over Replacement Player Rating, Box Plus-Minus, Win Shares, offensive rating, defensive rating, and time to return-to-play, and was collected for the season before and two seasons following injury.Results: Twenty-five NBA players with surgically treated complete Achilles ruptures met inclusion and exclusion criteria. The return-to-play rate from Achilles tendon ruptures from 1996-1997 to 2016-2017 was 80%, with a mean recovery period of 311.0 ± 100.9 days. After 2 years, performance significantly declined for Value over Replacement Player Rating, Box Plus-Minus, and offensive rating compared to controls and cases. However, there was no significant effect on defensive rating (P = 0.38). After two seasons, returning players had a Value over Replacement Player Rating that was 24.1% below pre-injury levels, contributed 1.4 fewer points per 100 possessions by Box Plus-Minus, and yielded 2.4 fewer wins by Win Shares.Conclusions: Achilles tendon rupture results in significant decreases in offensive production and career longevity. The injury does not have a significant impact on defensive production.Clinical relevance: Achilles tendon ruptures significantly affect basketball players ability to return-to-play, and their in-game performance.Level of evidence: 3.

Decision Support System Applications for Scheduling in Professional Team Sport. The Team's Perspective

Background: Periodization implies the systematic planning of training and competition with the goal of reaching the best possible performance in the most important competition. In team sports, this consists of finding a flight-and-practice schedule that maximizes the opportunities to perform the periodized contents (e.g., trips, practices, games, and days off). This process is conducted whilst considering known constraints (e.g., competitive schedule, roster availability, weather, especial events, holidays, or emotional effect of days away). The way a scheduling decision support system (DSS) leads users to make a decision should allow for flexibility, whilst minimizing users' confusion and facilitating the understanding of the recommendation given by the scheduling decision support system. Traditional approaches to solving scheduling problems use either simulation models, analytical models, heuristic approaches or a combination of these methods. When it comes to evaluate how the scheduling DSS is performing, three overarching aspects need to be reviewed: context satisfaction, process efficiency, and output quality. Appropriate training periodization and scheduling of trips and training sessions are critical for teams to optimize training and recovery processes in order to maximize health and performance. This article presents a methodological framework for designing decision-support systems for scheduling in professional team sports.

Concussion in National Football League Athletes Is Not Associated With Increased Risk of Acute, Noncontact Lower Extremity Musculoskeletal Injury

Background:

Impaired neuromuscular function after concussion has recently been linked to increased risk of lower extremity injuries in athletes.

Purpose:

To determine if National Football League (NFL) athletes have an increased risk of sustaining an acute, noncontact lower extremity injury in the 90-day period after return to play (RTP) and whether on-field performance differs pre- and postconcussion.

Study Design:

Cohort study, Level of evidence, 3.

Methods:

NFL concussions in offensive players from the 2012-2013 to the 2016-2017 seasons were studied. Age, position, injury location/type, RTP, and athlete factors were noted. A 90-day RTP postconcussive period was analyzed for lower extremity injuries. Concussion and injury data were obtained from publicly available sources. Nonconcussed, offensive skill position NFL athletes from the same period were used as a control cohort, with the 2014 season as the reference season. Power rating performance metrics were calculated for ±1, ±2, and ±3 seasons pre- and postconcussion. Conditional logistic regression was used to determine associations between concussion and lower extremity injury as well as the relationship of concussions to on-field performance.

Results:

In total, 116 concussions were recorded in 108 NFL athletes during the study period. There was no statistically significant difference in the incidence of an acute, noncontact lower extremity injury between concussed and control athletes (8.5% vs 12.8%; P = .143), which correlates with an odds ratio of 0.573 (95% CI, 0.270-1.217). Days (66.4 ± 81.9 days vs 45.1 ± 69.2 days; P = .423) and games missed (3.67 ± 3.0 vs 2.9 ± 2.7 games; P = .470) were similar in concussed athletes and control athletes after a lower extremity injury. No significant changes in power ratings were noted in concussed athletes in the acute period (±1 season to injury) when comparing pre- and postconcussion.

Conclusion:

Concussed, NFL offensive athletes did not demonstrate increased odds of acute, noncontact, lower extremity injury in a 90-day RTP period when compared with nonconcussed controls. Immediate on-field performance of skill position players did not appear to be affected by concussion.

Game Spacing and Density in Relation to the Risk of Injuries in the National Hockey League

Background

Ice hockey has significant workload demands. Research of other sports has suggested that decreased rest between games as well as an increased workload may increase the risk of injuries.

Purpose

To evaluate whether condensed game schedules increase the frequency and severity of injuries in the National Hockey League (NHL).

Study Design

Descriptive epidemiology study.

Methods

Data were obtained from publicly available online sources on game schedules and injuries for all NHL teams for the 2005-2006 through 2018-2019 seasons. Injury rates (per team per game) and the proportion of severe and nonsevere injuries were determined. The game-spacing analysis assessed the risk of injuries in relation to the number of days between games played (range, 0-≥6 days). The game-density analysis assessed the risk of injuries in relation to the number of games played within 7 days (range, 1-5 games). Results were assessed by analysis of variance, the post hoc Tukey test, and the chi-square test of distribution.

Results

The game-spacing analysis included 33,170 games and 7224 injuries, and a significant group difference was found (P = 1.44×10^-5), with the post hoc test demonstrating an increased risk of injuries when games were spaced with <1 day of rest. There was no significant difference in the ratio of severe to nonsevere injuries. The game-density analysis included 33,592 games and 10,752 injuries, and a significant group difference was found (P = 8.22×10^-48), demonstrating an increased risk of injuries with an increased number of games in all conditions except for the comparison between 4 versus 5 games in 7 days. There was also a significant difference in injury severity (P = .008), indicating that the least dense condition had a higher ratio of severe to nonsevere injuries compared with the other game-density conditions. Finally, the game-density analysis was repeated after excluding games played with <1 day of rest, and the finding of increased injury rates with increasingly condensed schedules remained significant (P = 9.52×10^-46), with significant differences between all groups except for the comparison between 1 versus 2 games in 7 days.

Conclusion

We found that a condensed schedule and <1 day of rest between games were associated with an increased rate of injuries in the NHL. These findings may help in the design of future game schedules.

The Business End of the Season: A Comparison Between Playoff and Regular-Season Workloads in Professional Basketball Players

PURPOSE

To quantify and compare the internal workloads experienced during the playoffs and regular season in basketball.

METHODS

A total of 10 professional male basketball players competing in the Italian first division were monitored during the final 6 weeks of the regular season and the entire 6-week playoff phase. Internal workload was quantified using the session rating of perceived exertion (s-RPE) method for all training sessions and games. A 2-way repeated-measures analysis of variance (day type × period) was utilized to assess differences in daily s-RPE between game days, days within 24 hours of games, and days >24 hours from games during the playoffs and regular season. Comparisons in weekly training, game, and total workloads were made between the playoffs and regular season using paired t tests and effect sizes.

RESULTS

A significant interaction between day and competitive period for s-RPE was found (P = .003, moderate). Lower s-RPE was apparent during playoff and regular-season days within 24 hours of games than all other days (P < .001, very large). Furthermore, s-RPE across days >24 hours from playoff games was different than all other days (P ≤ .01, moderate-very large). Weekly training (P = .009, very large) and total (P < .001, moderate) s-RPE were greater during the regular season than playoffs, whereas weekly game s-RPE was greater during the playoffs than the regular season (P < .001, very large).

CONCLUSIONS

This study presents an exploratory investigation of internal workload during the playoffs in professional basketball. Players experienced greater training and total weekly workloads during the regular season than during the playoffs with similar daily game workloads between periods.

Urgent wake up call for the National Basketball Association

NONE

Frequent air travel and the condensed game schedule typical of a National Basketball Association (NBA) team during the season, often results in accompanying sleep disturbances related to sleep length, sleep quality, and sleep timing (with highly harmful impacts on health, both physical and mental). These issues are not only problematic for NBA players, but also the coaches, training staff, and management support. In this narrative review, we summarize the detrimental effects that this travel and game schedule could have on NBA team members' sleep, as well as their physical and mental health. Multiple peer-reviewed articles address the role of sleep in athletic performance and health; however, to date, the literature focused on sleep-related issues that are unique to the NBA schedule is scarce. Firstly, this review addresses the impact of the NBA schedule, outlining the number of games and the travel involved (number of flights, the timing of flights, timings of arrival at destination and hotel); we also outline a typical daily NBA travel schedule, providing the reader a glimpse of what this encompasses. Secondly, we provide a brief overview of sleep science and discuss specific applications related to the NBA. Finally, we provide comment on the unique current situation of the NBA "bubble". Based on this review, there appears to be considerable scope for further investigation of the acute and chronic effects of sleep disturbances concerning the NBA travel and game schedule. Sleep science recommendations need to inform practice, target sleep interventions, and personalized protocols designed to enhance sleep health that can be incorporated at the organizational level.

Concussion Is Associated With Increased Odds of Acute Lower-Extremity Musculoskeletal Injury Among National Basketball Association Players

Purpose

To determine the odds of sustaining an acute lower-extremity (LE) musculoskeletal injury during the 90-day period after return-to-play (RTP) from concussion in National Basketball Association (NBA) athletes.

Methods

Concussion data for NBA players were collected from the 1999-2000 to 2017-2018 seasons, from publicly available sources. Age, position, injury, time to RTP, and demographic factors were collected. The 90-day period after each case of concussion was reviewed for acute noncontact LE musculoskeletal injury. Control athletes without a documented history of concussion were matched to concussed athletes by age, body mass index, position, and experience. Conditional logistic regression with a calculated odds ratio and a 95% confidence interval were used to assess the association between concussion and subsequent risk of LE injury.

Results

In total, 189 concussions were documented in 153 athletes. Of these, 140 cases were the first recorded instance of concussion in players with publicly available data. Thirty-six (25.7%) athletes sustained a LE injury within 90 days of concussion; 26 (20.2%) were non–season-ending and included in RTP analysis. The odds of sustaining an acute LE musculoskeletal injury within the 90-day period after concussion was 4.69 times greater in concussed players compared with controls (95% confidence interval 1.96-11.23, P < .001). There was no significant difference in games (4.2 ± 5.0 vs 4.7 ± 4.7 games, P = .566) or days (18.5 ± 39.1 days vs 10.9 ± 10.6 days, P = .912) missed between concussed players with LE injury and nonconcussed controls. The most common LE injuries in concussed athletes were ligament sprains/tears (65%).

Conclusions

Concussed NBA athletes have increased odds for sustaining an acute LE musculoskeletal injury within 90 days of RTP compared with nonconcussed controls. The most common injuries were ligament strains or tears. Changes in neuromotor control and proprioception following a concussion should be evaluated in high-level basketball players returning to sport.

Level of Evidence

Level III, Case-Control Study.

Cardiovascular fitness and health effects of various types of team sports for adult and elderly inactive individuals - a brief narrative review

Recreational team sports offer an alternative form of exercise to inactive individuals across the lifespan and sexes. Soccer is the most investigated recreational team sport reporting a wide range of health benefits, including cardiovascular (CV) health. The quest for novel paradigms to promote exercise in the general population, recently extended its interest to other team sports besides soccer. The available research supports the importance of recreational team handball, floorball, basketball, touch rugby, futsal and volleyball as training paradigms to improve CV fitness and other health-related variables in inactive individuals across ages and sexes. In most cases, recreational team sports programs assume the form of small-sided games, eliciting mean heart rates of 72-85% of the individual maximal. The majority of the training interventions were carried out for 12weeks with a reported mean attendance of 2 times 40-60min per week. Maximal oxygen uptake improvements were different in magnitude across the recreational team sports, with recreational team handball providing significant and clinically relevant increases (>3.5ml·kg^-1·min^-1). Game format, training exposure and pre-intervention health and fitness status are issues that need further investigation with the aim to optimize recreational team sports exercise programs implementation. Furthermore, the nature and effects of grassroots team sports should be further studied in order to provide as many as possible effective training tools for former practitioners and for the general population that has none or little experience of sport. Given the potential positive impact of recreational team sports practice on world population's health, large-scale randomized controlled trials are warranted.

Effect of Workload After ACL Reconstruction on Rerupture Rates in NBA Players

Background:

Rupture of the anterior cruciate ligament (ACL) is a common and potentially career-altering injury sustained by players in the National Basketball Association (NBA). Strategies have been employed by the league to prevent reinjury of players after ACL reconstruction (ACLR), including minute restrictions and rest games; however, it remains unknown whether workload metrics after ACLR influence the risk for reinjury and revision surgery.

Purpose:

To evaluate whether workload changes after return to play (RTP) from primary ACLR influences the risk of rerupture in NBA players.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

We identified NBA players from 1975 to 2018 who underwent primary ACLR as well as those who required revision ACLR. Primary outcomes included workload measures such as games played, games started, and minutes per game. Secondary outcomes included in-game performance statistics. Statistical analysis was used to compare relative workload and performance 3 years before and 3 years after undergoing primary ACLR. Workload was also compared between the control group of NBA players who underwent primary ACLR and those who required revision ACLR.

Results:

A total of 68 players who underwent primary ACLR were included, 8 of whom subsequently required revision ACLR. In their first season upon RTP, control players (primary ACLR) demonstrated a significant reduction in all workload metrics relative to the season before injury (P < .001), while the revision group demonstrated an unchanged to increased workload. In a comparison between the primary and revision groups during the first season after RTP, the primary group demonstrated significantly fewer games started (mean ± SD, 22.2 ± 3.0 vs 35.8 ± 8.3; P = .039) and minutes per game (20.5 ± 1.1 vs 27.0 ± 3.1; P = .048) than revision players. The primary ACLR group demonstrated reduced cumulative workload trends for the first 3 years after RTP relative to 3 years before injury, which was not demonstrated in the revision ACLR group, albeit statistically insignificant.

Conclusion:

Our study found that after ACLR, a reduction in workload parameters relative to preinjury baseline was associated with players who did not sustain rerupture. Further study is required to determine if workload measures following RTP from primary ACLR should be individualized relative to preinjury baseline.

Influence of power and maximal strength training on thermal reaction and vertical jump performance in Brazilian basketball players: a preliminary study

Study aim: To evaluate the effect of power and muscle strength training on skin temperature and the performance of the vertical jump with countermovement (CMJ).

Material and methods: The sample consisted of four male basketball athletes of the under-17 category (age: 15.75 ± 1.0 years). 48 hours after anthropometric evaluation and determination of the loads for 1 repetition maximum (1RM) in the leg extension exercise, the athletes were subjected, through crossover-type entrance, to power (PTP) and strength (STP) training protocols. The protocols consisted of three sets with loads of 60% and 90% of 1RM for PTP and STP, respectively. Thermographic images of the thighs were taken before and immediately after each training session.

Results: There were significant differences in results between the two training protocols, with increased total repetitions (t = 13.481; p < 0.05) and total training volume (t = 15.944; p < 0.05) in the PTP, and increase in the % of 1RM (t = 33.903; p < 0.05) and rating of perceived exertion (t = 6.755; p < 0.05) in the STP. The skin temperature before and after PTP and STP showed no significant differences. In the post-STP, the CMJ presented significant reductions in height (t = 3.318; p < 0.05), flight time (t = 3.620; p < 0.05), velocity (t = 3.502; p < 0.05), and force (t = 4.381; p < 0.05). There were no significant differences in pre-and post-STP CMJ.

Conclusions: Power and maximum strength training in the leg extension exercise performed until concentric failure appears to be a method that induces thermal stress on the skin. This training directly influenced the performance of the vertical jump after the stimulus.

Epidemiology and Video Analysis of Achilles Tendon Ruptures in the National Basketball Association

BACKGROUND

There is a paucity of literature regarding risk factors and mechanisms of Achilles tendon (AT) ruptures in the National Basketball Association (NBA).

PURPOSE

To identify the risk factors and outcomes of AT ruptures in NBA athletes. Furthermore, using video analysis, to characterize the mechanisms of rupture by identifying the most common playing situations and lower extremity positions at the time of injury.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

AT ruptures in the NBA that occurred between the seasons of 1969-1970 and 2017-2018 were identified. Player data collected included age, position, body mass index, total games started before and after injury, and Player Efficiency Rating. Injury-related variables collected included date of injury, laterality, minutes played before injury, operative versus nonoperative treatment, and time to return to play. Available video footage was analyzed for the mechanism and body position at the time of injury. Univariable and multivariable linear regression was used to compare changes in performance before and after AT rupture. Statistical significance was set at P < .05.

RESULTS

Forty-four ruptures were identified between 1970 and 2018. The mean age was 28.3 years, with players averaging 6.8 seasons before AT rupture. AT ruptures were most prevalent during early-season game play (27.3%), followed by preseason (18.2%) and late season (18.2%). More than a third (36.8%) of players either did not return to play or started in fewer than 10 games in the remainder of their career, with 21% of ruptures leading to retirement. The mean time to return to play was 10.5 months. The Player Efficiency Rating declined by an average of 2.9 points (range, -11.5 to +2.3) (P < .001). Analysis of available injury footage (n = 12) demonstrated all ruptures to be noncontact in nature, most commonly occurring just before takeoff as the player began to push off from a stopped position, with the foot in dorsiflexion, the knee in early flexion, and the hip in extension.

CONCLUSION

In the NBA, a majority of AT ruptures occur early in the season, in veteran players, with almost half not returning to play or starting fewer than 10 games in the remainder of their career. The most common mechanism of injury is taking off from a stopped position just before toe-off in a dorsiflexed foot.

The Negative Influence of Air Travel on Health and Performance in the National Basketball Association: A Narrative Review

Air travel requirements are a concern for National Basketball Association (NBA) coaches, players, and owners, as sport-based research has demonstrated short-haul flights (≤6 h) increase injury risk and impede performance. However, examination of the impact of air travel on player health and performance specifically in the NBA is scarce. Therefore, we conducted a narrative review of literature examining the influence of air travel on health and performance in team sport athletes with suggestions for future research directions in the NBA. Prominent empirical findings and practical recommendations are highlighted pertaining to sleep, nutrition, recovery, and scheduling strategies to alleviate the negative effects of air travel on health and performance in NBA players.