NFL Foundation

ObjectivesThe purpose of this study was to (1) establish the agreement of multiple expert reviewers’ identification of hamstring strain injury (HSI) scenarios and related body postures among National Football League (NFL) players and (2) determine the prevalence of each HSI scenario and associated body posture in the NFL between 2018 and 2022.MethodsVideos from 305 HSIs in the NFL were reviewed in a blinded fashion by two expert reviewers, who classified the injuries into seven predefined injury scenarios developed by a separate committee of experts. Lower extremity body postures were also identified. Cohen’s Kappa coefficients were calculated to determine inter-rater agreement and used to select the subset of injuries to be described via injury scenario and body posture with the intent of minimising bias or ambiguity in reporting.Results137/305 (45%) injury videos met the criteria for inclusion in the final dataset based on assessment of classification agreement. Agreement in injury scenario and body posture ranged from poor to moderate. Sprinting injuries were the most common scenario (59/137, 43%). Unique scenarios specific to American football demonstrated the importance of excessive trunk flexion during contact, or during acceleration and change of direction (54/137, 39%).ConclusionsUsing a systematic approach involving multiple expert reviewers, sprint-related injury scenarios were highlighted as the most common injury scenario for HSIs. Specific to American football; however, excessive trunk flexion during contact plays or during acceleration and change of direction may be important to consider for injury prevention or rehabilitation from HSIs.

Maximal muscle strength is often assessed with single-joint or repetition-maximum testing. The purpose of this study was to evaluate the reliability of countermovement-jump (CMJ) velocity-load testing and assess the relationship between CMJ velocity-load kinetics and concentric-isometric-eccentric multijoint leg-extension strength tested on a robotic servomotor leg press in trained athletes. University athletes (N = 203; 52% female) completed 3 concentric, isometric, and eccentric maximum voluntary leg-extension contractions on the robotic leg press, followed by CMJ velocity-load testing with an additional external load of 0% (CMJBW), 30% (CMJ30), and 60% (CMJ60) of body mass. A linear model was fit for the CMJ takeoff velocity-load relationship to obtain the load intercept. Force-velocity parameters were obtained for the CMJ eccentric deceleration and concentric phases. Linear mixed-effects models were constructed to predict concentric, isometric, and eccentric leg-press force using the CMJ takeoff velocity-load relationship and CMJ kinetics. Isometric leg-press strength was predicted by load intercept and sex (P < .001, R2 = .565, prediction error = 14%). Concentric leg-press strength was predicted by load intercept, CMJ60 concentric impulse, and sex (P < .001, R2 = .657, prediction error = 10%). Eccentric leg-press strength was predicted by minimum downward velocity, CMJ60 eccentric deceleration impulse, and sex (P < .001, R2 = .359, prediction error = 14%). Given the relevance of muscle-strength testing for sport performance and injury prevention, assessing force-velocity mechanics with loaded CMJ testing is a reliable and viable approach to predict maximal concentric, isometric, and eccentric leg-press strength in competitive athletes.

Background: Microfragmented adipose tissue has been proposed for intra-articular treatment of knee osteoarthritis. There are little data comparing the outcomes of treatment between microfragmented adipose tissue and other biological treatments. Purpose: To perform a systematic review and meta-analysis comparing microfragmented aspirated fat injections to other orthobiologics, hyaluronic acid, and corticosteroid injections for symptomatic knee osteoarthritis. Study Design: Systematic review and meta-analysis; Level of evidence, 2. Methods: A systematic review of the literature was performed to identify pertinent publications in the MEDLINE, Embase, Scopus, and Google Scholar databases, including all level 1 to 3 studies from 2000 to 2023. Validated knee scores (visual analog scale [VAS] for pain, Knee injury and Osteoarthritis Outcome Score [KOOS], Lysholm, International Knee Documentation Committee) were included as outcome measures. Risk of bias was assessed using Cochrane tools. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of the body of evidence and the modified Coleman Methodology Score was used to assess study quality. Heterogeneity was assessed using χ2 and I2 statistics. Results: Five studies were included in the analysis. One study had a high risk of bias; 4 studies had some risk of bias. The overall study quality was fair, and the certainty of evidence was low. The pooled estimate for VAS scores did not demonstrate significant differences at 3, 6, and 12 months. The pooled estimate for the KOOS Pain, Symptoms, Activities of Daily Living, Sport and Recreation, and Quality of Life subscales did not demonstrate significant differences at 3, 6, and 12 months. Conclusion: The results of this systematic review and meta-analysis demonstrated that there were no statistically significant differences for both the clinical outcomes and pain scores between microfragmented adipose tissue and other orthobiologics for the treatment of knee osteoarthritis. However, modest study quality, some risk of bias, and low certainty of evidence reduce external validity, and these results must be viewed with some caution.

ObjectiveTo compare the severity of head impacts between professional and Division I (D-I) collegiate football games for the purpose of improving protective equipment.MethodsA total of 243 football players from the National Football League (NFL) and from D-I of the National Collegiate Athletic Association (NCAA) were equipped with instrumented mouthpieces capable of measuring six degrees-of-freedom head kinematics. Head impacts were processed using a custom algorithm and combined with game period descriptors to produce a curated dataset for analysis. Head impact severity distributions for several kinematic-based metrics were compared within position groupings between leagues.ResultsA total of 11 038 head impacts greater than 10 g from 1208 player-games were collected during 286 player-seasons (2019–2022). No significant differences were found between leagues in the distributions of kinematic-based metrics for all investigated position groupings (p≥0.320). The median and IQRs for peak linear acceleration for NFL and NCAA were 17.2 (9.3) g and 17.0 (8.6) g for linemen, 20.7 (13.8) g and 20.0 (13.5) g for hybrid and 21.0 (17.0) g and 20.8 (15.5) g for speed position groupings, respectively.ConclusionThe absence of statistically significant differences in the distributions of head impact severity between professional and D-I collegiate football players indicates that these data can be combined for the purpose of understanding the range of loading conditions for which new protective equipment, such as position-specific helmets, should be designed. This observation underscores the potential for knowledge transfer regarding biomechanical factors affecting head loading across professional and D-I college football, highlighting crucial implications for innovation in protective equipment.

ObjectiveDescribe concussion incidence across the National Football League (NFL).DesignDescriptive epidemiology study.SettingConcussions sustained during NFL offseason, preseason (PS), regular season (RS), and postseason team-related activities from 2015–2019.ParticipantsActive NFL players.InterventionsFocused concussion reduction efforts in 2018, including better-performing helmets, prohibition of use of helmet to initiate contact and other safety-focused rules changes, and player/Club education.Outcome MeasuresConcussion.Main ResultsA total 1,301 concussions were identified from 2015–2019 among 1,003 players, including 1,046 (80%) in games, 221 (17%) during in-season practices, and 34 (3%) in offseason and conditioning activities. Of the 221 in-season practice concussions, 175 (79%) occurred in PS practices, with the majority (n=129) occurring during Training Camp. Concussion rates were 0.31/team-game in RS and 0.35/team-game in PS, which were higher than practice rates (RS: 0.01/team-practice; PS: 0.05/team-practice). Notably, the average annual incidence of in-season concussions during practices and games decreased by 18% from 273.3 in 2015–2017 to 223.5 in 2018–2019 (p<0.01), driven by a 23% decrease in game concussions (2015–2017: 230.7 vs. 2018–2019: 177.0; p<0.01). This decrease followed the focused concussion reduction efforts implemented in 2018. In RS games most concussions were sustained on running and passing plays (n=119/season), but the highest average rate per play was on kickoffs (0.69/100 plays).ConclusionsConcussions in the NFL are a key focus for player safety. Concussion reduction strategies implemented prior to 2018 led to a sustained decrease in concussion incidence, providing a new benchmark from which to work toward further reduction.

Publicly obtained data (POD) have recently been utilized frequently by sports medicine researchers to describe injury patterns, risk factors, and outcomes in elite athletes. The relative ease of this type of research that is based solely on internet and media sources has resulted in a near exponential increase in the number of these POD studies. To systematically review the sports medicine literature for studies based solely on POD. Systematic review and bibliometric analysis; Level of evidence, 4. A systematic review of POD studies published since 2000 was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies of interest were those relying on publicly available injury reports or online media for data acquisition in collegiate, semiprofessional, and professional athletes. There were 209 POD studies published between 2000 and 2022, with 173 (82.8%) of these studies published after 2016. Studies were published most frequently on athletes participating in North American professional leagues: National Football League (n = 69 [28.4%]), Major League Baseball (n = 56 [23.0%]), National Basketball Association (n = 37 [15.2%]), and National Hockey League (n = 33 [13.6%]). The most common injuries assessed were head injuries/concussions (n = 43 [21.1%]), anterior cruciate ligament injuries (n = 33 [16.2%]), and ulnar collateral ligament injuries (n = 23 [11.3%]). One-quarter of the studies (n = 53 [25.4%]) reported only 1 POD source, and 1 study (0.5%) reported no source. Additionally, 65 studies (31.1%) listed nonspecific POD resources or solely cited previous literature to describe the POD search methodology and data acquisition. POD studies are exponentially increasing in number, particularly across major North American professional sports leagues, with significant variability in the injury of interest, search methodology, and number of data sources. The accuracy of the conclusions reached based on the POD methodology appears highly variable. Given the potential impact of these publications as both contributors to current knowledge and drivers of future research, the sports medicine community should be aware of the inherent biases and limitations of POD injury studies.

Bisnis kuliner (Papa John’s) seperti dominos, pizza hut dan Little Caesars pada tahun 90-an ada di mana-mana mengalami kenaikan (rise). Namun pada akhir tahun 1990, industri kuliner ini mengalami penurunan (fall). Studi ini bertujuan untuk mengetahui alasan penurunan (fall) dan atau kenaikan (rise) pada bisnis Papa John’s. Studi ini menggunakan studi kasus tunggal pada bisnis Papa John’s yang bergerak di bidang kuliner dengan analisis business model canvas, business pattern, business environment &amp;amp; value proposition canvas. Bisnis kuliner ini pernah menjadi tren pertumbuhan dan sukses karena value proposition mengutamakan kualitas dengan menggunakan bahan baku segar dan terbaik. Namun, bisnis kuliner Papa John’s mengalami penurunan karena key activies memfokuskan kepada proses pembuatan pizza dan pemasaran produk seperti bekerja sama dengan NFL. Studi merekomendasikan key activities membuat konsep serta membentuk manajemen baru.

Hill, Kevin P. MD, MHS; Wu, Andrew MD; Solomon, Gary S. PhD; Mack, Christina PhD, MSPH, FISPE; Ling, Geoffrey MD, PhD; Mayer, Thom MD, FACEP, FAAP, FACHE; Sills, Allen K. MD Author Information