Defensive Linemen Research Articles

Position-Specific Differences in Speed Profiles Among National Football League Scouting Combine Participants.

Gillen, ZM. Position-specific differences in speed profiles among NFL scouting combine participants. J Strength Cond Res XX(X): 000-000, 2024-This study examined the relationships between speed profiles and athletic performance measurements from the National Football League (NFL) Scouting Combine, and position-specific differences in speed profiles. Subjects included NFL Scouting Combines participants with valid scores for the 40-yard dash, as well as the 10- and 20-yard splits of the 40-yard dash (n = 2,156). Subjects were divided into the following position groups: defensive backs (DBs, n = 421), defensive linemen (DL, n = 356), linebackers (LBs, n = 261), offensive linemen (OL, n = 354), running backs (RBs, n = 217), tight ends (TEs, n = 122), quarterbacks (QBs, n = 108), and wide receivers (WRs, n = 317). Performance measures included 40-yard dash time (with 10- and 20-yard split times), bench press repetitions to failure, vertical jump height, broad jump distance, pro-agility time, and L-cone drill time. The 40-yard dash and its splits calculated vmax, τ, and amax to reflect speed profiles. One-way analysis of variances examined position-related differences. Pearson's product moment correlation coefficients examined relationships between performance measures and speed profile variables. Skill positions (DB and WR) had the greatest vmax and amax, and lowest τ, followed by big skill positions (LB, RB, TE, QB), followed by DL, then OL with the lowest vmax and amax, and highest τ. For skill and big skill positions, vmax, τ, and amax exhibited greater relationships with combine measures, whereas OL generally had the lowest relationships. The position-specific differences in this study demonstrate potential areas of strength and weakness for certain positions. This may help guide strength and conditioning coaches desiring to improve position-specific speed and acceleration capabilities for American football players.

Muscle-to-Bone Ratio in NCAA Division I Collegiate Football Players by Position.

Dengel, DR, Studee, HR, Juckett, WT, Bosch, TA, Carbuhn, AF, Stanforth, PR, and Evanoff, NG. Muscle-to-bone ratio in NCAA Division I collegiate football players by position. J Strength Cond Res 38(9): 1607-1612, 2024-The purpose of this study was to compare the muscle-to-bone ratio (MBR) in National Collegiate Athletic Association Division I football players (collegiate football players [CFP]) to healthy, age-matched controls. In addition, we examined MBR in CFP by position. A total of 553 CFP and 261 controls had their total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) determined by dual x-ray absorptiometry (DXA). College football players were categorized by positions defined as offensive linemen (OL), defensive linemen (DL), tight end, linebacker (LB), running back (RB), punter or kicker, quarterback (QB), defensive back (DB), and wide receiver (WR). There were significant differences between CFP and controls for total LM (80.1 ± 10.0 vs. 56.9 ± 7.8 kg), FM (22.2 ± 12.5 vs. 15.2 ± 7.1 kg), and BMC (4.3 ± 0.5 vs. 3.1 ± 0.5 kg). Although there were significant differences in body composition between CFP and controls, there was no significant differences in total MBR between CFP and controls (18.6 ± 1.4 vs. 18.8 ± 1.7). Regionally, CFP had significantly lower trunk MBR than controls (26.7 ± 2.7 vs. 28.7 ± 4.2), but no difference was seen in leg or arm MBR. Positional differences in CFP were noted as total MBR being significantly higher in DL (19.0 ± 1.4) than in DB (18.1 ± 1.3), WR (18.1 ± 1.3), and LB (18.2 ± 1.3). OL had a significantly higher total MBR (19.2 ± 1.3) than DB (18.1 ± 1.3), LB (18.2 ± 1.3), QB (18.1 ± 1.0), and WR (18.1 ± 1.3). In addition, RB had significantly higher total MBR (18.8 ± 1.3) than DB (18.1 ± 1.3) and WR (18.1 ± 1.3). This study may provide athletes and training staff with normative values when evaluating total and regional MBR with DXA.

Does the Scouting Combine Influence a Player's Standing in the NFL Draft?

The annual scouting combine gives National Football League (NFL) teams an opportunity to assess over four days the skills of that year’s most promising college football players. The authors merge two data sets on over one thousand draft eligible football players spanning the ten-year period between 2014 and 2023 on their ultimate draft pick numbers and selected combine test results. Combine test results are converted to z-scores, that is, each participant’s number of standard deviations above or below the average performance in that year’s particular combine test. Wide receivers’ standing in the NFL’s draft correlates well with combine test results in the 40-yard dash. However, the authors find little-to-no relationship between combine test results and draft pick status over the last five years (let alone the last ten) for defensive backs, running backs, and defensive linemen who participated in, respectively, the vertical leap, broad jump, and bench press repetitions.

Efficacy of Guardian Cap Soft-Shell Padding on Head Impact Kinematics in American Football: Pilot Findings.

Sport-related concussion prevention strategies in collision sports are a primary interest for sporting organizations and policy makers. After-market soft-shell padding purports to augment the protective capabilities of standard football helmets and to reduce head impact severity. We compared head impact kinematics [peak linear acceleration (PLA) and peak rotational acceleration (PRA)] in athletes wearing Guardian Cap soft-shell padding to teammates without soft-shell padding. Ten Division I college football players were enrolled [soft-shell padding (SHELL) included four defensive linemen and one tight end; non-soft-shell (CONTROL) included two offensive linemen, two defensive linemen, and one tight end]. Participants wore helmets equipped with the Head Impact Telemetry System to quantify PLA (g) and PRA (rad/s2) during 14 practices. Two-way ANOVAs were conducted to compare log-transformed PLA and PRA between groups across helmet location and gameplay characteristics. In total, 968 video-confirmed head impacts between SHELL (n = 421) and CONTROL (n = 547) were analyzed. We observed a Group x Stance interaction for PRA (F1,963 = 7.21; p = 0.007) indicating greater PRA by SHELL during 2-point stance and lower PRA during 3- or 4-point stances compared to CONTROL. There were no between-group main effects. Protective soft-shell padding did not reduce head impact kinematic outcomes among college football athletes.

Determining the True Incidence of Glenohumeral Instability Among Players in the National Football League: An Epidemiological Study of Non-Missed Time Shoulder Instability Injuries.

Shoulder instability encompasses a spectrum of glenohumeral pathology ranging from subluxation to dislocation. While dislocation frequently leads to removal from play, athletes are often able to play through subluxation. Previous research on glenohumeral instability among athletes has largely focused on missed-time injuries, which has likely disproportionately excluded subluxation injuries and underestimated the overall incidence of shoulder instability. To describe the epidemiology of shoulder instability injuries resulting in no missed time beyond the date of injury (non-missed time injuries) among athletes in the National Football League (NFL). Descriptive epidemiology study. The NFL's electronic medical record was retrospectively reviewed to identify non-missed time shoulder instability injuries during the 2015 through 2019 seasons. For each injury, player age, player position, shoulder laterality, instability type, instability direction, injury timing, injury setting, and injury mechanism were recorded. For injuries that occurred during games, incidence rates were calculated based on time during the season as well as player position. The influence of player position on instability direction was also investigated. Of the 546 shoulder instability injuries documented during the study period, 162 were non-missed time injuries. The majority of non-missed time injuries were subluxations (97.4%), occurred during games (70.7%), and resulted from a contact mechanism (91.2%). The overall incidence rate of game-related instability was 1.6 injuries per 100,000 player-plays and was highest during the postseason (3.5 per 100,000 player-plays). The greatest proportion of non-missed time injuries occurred in defensive secondary players (28.4%) and offensive linemen (19.8%), while kickers/punters and defensive secondary players had the highest game incidence rates (5.5 and 2.1 per 100,000 player-plays, respectively). In terms of direction, 54.3% of instability events were posterior, 31.9% anterior, 8.5% multidirectional, and 5.3% inferior. Instability events were most often anterior among linebackers and wide receivers (50% and 100%, respectively), while posterior instability was most common in defensive linemen (66.7%), defensive secondary players (58.6%), quarterbacks (100.0%), running backs (55.6%), and tight ends (75.0%). The majority of non-missed time shoulder instability injuries (97.4%) were subluxations, which were likely excluded from or underreported in previous shoulder instability studies due to the inherent difficulty of detecting and diagnosing shoulder subluxation.

Percentile Rankings and Position Differences for Absolute and Allometrically Scaled Performance Measures From the National Football League Scouting Combine.

Gillen, ZM. Percentile rankings and position differences for absolute and allometrically scaled performance measures from the National Football League scouting combine. J Strength Cond Res 37(12): e613-e624, 2023-This study aimed to provide percentile rankings for absolute and allometrically scaled performance measures for National Football League (NFL) Scouting Combine subjects and determine if allometric scaling affected position-specific differences in performance measures. Subjects included American football players ( n = 3,015) who participated in the NFL Scouting Combines between 2015 and 2019. Subjects were divided into position groups: defensive backs (DBs, n = 562), defensive linemen (DL, n = 498), linebackers (LBs, n = 395), offensive linemen (OL, n = 505), running backs (RBs, n = 303), tight ends (TEs, n = 165), quarterbacks (QBs, n = 165), and wide receivers (WRs, n = 422). Performance measures included 40-yd dash time (with 10- and 20-yd split times), bench press repetitions to failure, vertical jump height, broad jump distance, pro-agility time, and L-cone drill time. Descriptive statistics were computed for all performance metrics and allometrically scaled performance metrics. One-way analyses of variance tested for position group differences for absolute and allometrically scaled performance measures. Percentile rankings for absolute and allometrically scaled performance measures were determined. Position-specific differences for absolute performance measures indicated that DB and WR tended to be faster, jump higher and further, and have greater change-of-direction capabilities compared with LB, QB, RB, and TE, who scored better in these respects than OL and DL. Allometric scaling revealed that DL, LB, RB, and TE tended to have superior performance than DB and WR, with QB and OL having the poorest performance. This study provides percentile rankings and the equation and parameters by which coaches and practitioners may allometrically scale data for evaluations of normalized performance measures from the NFL Scouting Combine.

Return to Play, Performance, and Economic Analysis of National Football League Players After Lisfranc Injury.

A Lisfranc injury can occur to either the ligament or bone, which causes instability when attempting to perform strength and balance maneuvers. The study's aims were to (1) analyze the return-to-play (RTP) rate and performance level of players in the National Football League (NFL) after Lisfranc injury and (2) determine the economic and financial impact of Lisfranc injuries to the NFL. We hypothesized that there would be a low RTP rate following Lisfranc injury in the NFL. Case series; Level of evidence, 4. Multiple online public records were used to identify NFL players with Lisfranc injuries between the 2009 and 2020 seasons. Players were assessed according to their RTP statistics: snap count, approximate value (AV), games played, and games started. Nonparametric methods were used to compare player statistics before and after injury. Also, player salaries while injured were calculated (in 2022 US dollars after adjusting for inflation) to approximate economic loss for those players who returned to play. A total of 33 NFL athletes sustained a Lisfranc injury during the study period. Most Lisfranc injuries were experienced by offensive linemen (n = 8; 24.2%), followed by running backs (n = 7; 21.2%). Overall 27 players (81.8%) returned to play after injury at a median of 11.0 months (IQR, 10.2-11.8 months). There were no significant differences between pre- and postinjury snap counts or number of games played and started. In terms of player performance, there was a statistically significant decrease in AV at 1 year postinjury (median [IQR], 6.0 [4.0-10.0] preinjury vs 5.0 [2.5-7.5] postinjury; P = .022). The overall cost of recovery amounted to $104.7 million, with quarterbacks (n = 4) accounting for the greatest cost at $32.6 million. The next 2 most expensive positions were offensive and defensive linemen (n = 5 each) at $19.4 million each. Our results did not support the hypothesis, as the RTP rate for NFL athletes sustaining Lisfranc injuries was 81.8%. This injury was associated with a significant decrease in AV 1 year postinjury. In terms of economic impact, quarterbacks accounted for almost one-third of expenses while constituting only 14.8% of injuries.

The Effect of Probable COVID-19 Infection on the National Football League Players' Performance and Endurance During the 2020 Season.

Objective The objective of this study was to assess whether the National Football League (NFL) players with probable coronavirus disease 2019 (COVID-19) during the 2020 season experienced a decline in athletic performance and endurance. Methods All players who were listed on the NFL's COVID-19 Injury Reserve (COVID-IR) list were screened for inclusion. Players were included in the study if they had spent ≥10 days on the COVID-19 IR list (which indicated a positive PCR test based on the NFL COVID-19 policies), had played in at least two games before and after going on the IR list, and primarily played an offensive or defensive position. The mean number of snaps played per game and Pro Football Focus (PFF) score per game were collected for each athlete, which served as surrogate measures of endurance and performance, respectively. The results were analyzed with players grouped by position, and then all players grouped as a whole. Within-group comparisons were performed via t-tests. Results A total of 78 players met the criteria for inclusion in the study. The overall mean PFF score pre-COVID-19 infection was 62.15 (SD: 6.93), while it was 61.73 (SD: 7.42) post-COVID-19 infection, showing a decrease of 0.42 after infection (n=78, p=0.33). The mean number of snaps played per game pre-COVID-19 infection was 38.99 (SD: 16.46) while it was38.10 (SD: 17.05) post-COVID-19 infection, showing a decrease of 0.89 after infection (n=78, p=0.30). When grouped by position, statistically significant differences were seen with Defensive Backs' mean snaps played per game decreasing by 18.30 (n=6, p=0.03) and Defensive Linemen's mean PFF score decreasing by 3.77 points (n=21, p=0.03). Conclusion Based on our findings, COVID-19 infection negatively impacted endurance in Defensive Backs, and performance in Defensive Linemen. However, there was inconclusive evidence to show whether COVID-19 infection negatively impacted other positions when analyzed separately or all positions when analyzed together. Further studieswith more participants are needed to fully assess the effects of COVID-19 on performance and endurance in elite athletes.

The Paradoxical Big Nonstory: Traditional and Social Media Frames Surrounding Carl Nassib, the NFL's First Openly Gay Player

Abstract: In June of 2021, National Football League (NFL) defensive lineman Carl Nassib made history as the first openly gay, active professional football player to come out. Advancing research about news coverage of LGBT athletes, this paper employs content analysis to analyze the frames used in newspaper articles ( n = 195) and on social media ( n = 5,588 tweets) to report the story of Nassib's coming out. This study examines the media frames that were used most frequently in covering Nassib's coming out and discusses the significant differences between traditional media and those used most widely on social media. Findings indicate overall support for Nassib's coming out, as both newspapers and Twitter posts framed the story as a watershed moment and focused on celebrity support; however, personal attacks were more common on social media. Implications for how media cover gay-athlete stories are discussed.

Profile of Caloric Needs of Football Athletes by Position in Football School

The purpose of writing this article is to find out and recommend calorie and energy profiles in shaping the stamina of football athletes in football schools. The search for this article uses a qualitative descriptive method through literature studies sourced from references that are willing to be studied conceptually and inferred from the results of the discussion. The results of this study show that the average calorie needs in the Defensive Lineman position requires as much as 6,100 - 6,400 kilo calories, in the Offensive Lineman position it requires as much as 6,200-6,500 kilo calories, in the Running Back position it requires as much as 5,700-6,000 kilo calories, in the Tight End position it requires as much as 6,000-6,300 kilo calories, the Linebacker needs as many as 5,900-6,200 kilo calories, and, in the Quarterback position, it needs as many as 5,200-5,400 kilo calories. Furthermore, the fulfillment of balanced nutrition for SSB football athletes that must be applied conditionally and proportionally is as follows Calories for football athletes are needed at 3542-4693 kilo calories per athlete per day, carbohydrate fulfillment for athletes as much as 531703 grams per athlete per day, protein fulfillment as much as 132-175 grams per athlete pr day, and fat fulfillment is needed at 118-156 grams per athlete per day.

Hamstring injuries in the national football league: An epidemiological study

BackgroundWhile numerous studies have evaluated National Football League injuries, there is limited literature evaluating hamstring injuries sustained in games. Our primary aim is to analyze the effect of player position on the relative incidence of hamstring injuries in the National Football League. Our secondary aims are to analyze the effects of field surface, week of the season, and short rest weeks. MethodsOfficial National Football League game books containing injury data from the 2013–2016 regular seasons were used. Data were analyzed to determine the incidence of hamstring injuries by field surface, rest, and week of the season. Field surface was considered either turf or grass. Short rest was considered four days. Relative incidence of hamstring injuries by position was performed with standardized incidence ratios. P values < 0.05 were considered statistically significant. ResultsSeventy-eight qualifying hamstring injuries were identified and included in our analysis. Linebackers had the highest relative incidence per play with a standardized incidence ratio of 2.02 (CI: 1.14–2.91), followed by Defensive Backs (1.62; 95% CI: 1.14–1.62). Offensive linemen and defensive linemen had standardized incidence ratios significantly less than 1. Fifty-seven percent of hamstring injuries occurred on turf fields (p = 0.082). There was no significant difference between the proportion of hamstring injuries that occurred on short rest and the proportion of games played on short rest (p = 0.959). Hamstring injuries were not more likely to occur than the pooled group of all other types of injuries on short rest (p = 0.861). With a 17-week season, the mean week of hamstring injury was 8.05 (95% CI: 7.06–9.04), while the median week was 7.5. ConclusionsLinebackers and Defensive Backs have the highest relative incidence of hamstring injuries compared to other position groups, while offensive and defensive linemen have the lowest. Field surface and a short rest period did not show significance.

Player Position and Labral Tear Location and Size in NCAA Division I Football Players Undergoing Arthroscopic Surgery.

Shoulder instability attributed to glenoid labral tears is common among National Collegiate Athletic Association (NCAA) football players. Certain repetitive activities by player position may contribute to instability. To compare the location of labral tears among player positions in NCAA Division I football. Cross-sectional study. We conducted a review of football players who underwent shoulder labral repair between 2000 and 2020 at a single institution. Inclusion criteria were NCAA Division I level, diagnosis of shoulder instability, and labral tear requiring arthroscopic repair. Exclusion criteria were prior surgery on injured shoulder and incomplete medical records. Players were divided into 3 groups: line players (offensive and defensive linemen, defensive end), skill players (defensive back, wide receiver, running back, and quarterback), and hybrid players (linebacker and tight end). Labral tear location and size were recorded using the clockface method and categorized into 6 zones: superior, anterosuperior, anteroinferior, inferior, posteroinferior, and posterosuperior. Comparison of variables was performed using chi-square test or Fisher exact test (categorical) and 1-way analysis of variance or Kruskal-Wallis H test (continuous). The Spearman rank-order correlation was used to assess relationships between continuous data. Of the 53 included players, 37 (70%) were offensive linemen, defensive linemen, and linebackers. There were 29 line players, 11 skill players, and 13 hybrid players. Line players represented 55% of included players and had the most total labral tears as compared with all groups. Hybrid players had a significantly higher percentage of posterosuperior tears than line players (92% vs 52%; P = .015) and skill players (92% vs 27%; P = .002). Skill players had a significantly higher percentage of anterior tears at 3:00-4:00 and 5:00-6:00 when compared with hybrid players (82% vs 15%, P = .003; 82% vs 31%, P = .012, respectively). There was a positive correlation between labral tear size and number of suture anchors (0; P = .010). In this study of NCAA Division I football players, skill players had a higher proportion of anteroinferior labral tears, and hybrid players had a higher proportion of posterosuperior labral tears.

Kinanthropometric Characteristic Comparisons of NCAA Division I Offensive and Defensive Linemen Spanning 8 Decades.

Jacobson, BH, Dawes, J, Smith, D, and Johnson, Q. Kinanthropometric characteristic comparisons of NCAA Division I offensive and defensive linemen spanning eight decades. J Strength Cond Res 36(12): 3404-3408, 2022-College football players have gained body mass, stature, and speed since the inception of the game. Of particular note is the body mass gain of NCAA Division I offensive linemen (OL) and defensive linemen (DL). The primary purpose of this study was to compare body mass and stature of OL and DL for each decade since 1950 and to subsequently compare speed using more recently available NFL Combine data to determine if the rates of gain have been consistent or is waning. Ten universities were randomly chosen from the "Power Five" conferences based on the prominence of their football programs. Recorded data included players' body mass, stature, and available 40 yd times. For each team, 8 OL and 8 DL were chosen, totaling 80 OL and 80 DL. Results indicated that body mass increased significantly ( p < 0.05) for both OL and DL (57.9 and 54.4%, respectively). However, the rate of weight gain for either OL or DL was not linear. Both OL and DL consistently increased in height from 1950 with OL and DL increasing 12.7 cm (5.0 in) and 11.4 cm (4.7 in), respectively. In addition, 40 yd times have improved over the 3 available decades (2000-2020). The 2020 times were significantly faster than the 2000 for both OL and DL. These findings may have profound implications related to player safety. The overall increases in body mass of linemen in combination with greater speed may result in have devastating consequences to the human body in a contact/collision sport such as football. Indeed, new rules are being considered to reduce debilitating injures.

Effect of Player Position on Serum Biomarkers during Participation in a Season of Collegiate Football.

This prospective cohort study examined the relationship between a panel of four serum proteomic biomarkers (glial fibrillary acidic protein [GFAP], ubiquitin C-terminal hydrolase-L1 [UCH-L1], total Tau, and neurofilament light chain polypeptide [NF-L]) in 52 players from two different cohorts of male collegiate student football athletes from two different competitive seasons of Division I National Collegiate Athletic Association Football Bowl Subdivision. This study evaluated changes in biomarker concentrations (as indicators of brain injury) over the course of the playing season (pre- and post-season) and also assessed biomarker concentrations by player position using two different published classification systems. Player positions were divided into: 1) speed (quarterbacks, running backs, halfbacks, fullbacks, wide receivers, tight ends, defensive backs, safety, and linebackers) versus non-speed (offensive and defensive linemen), and 2) "Profile 1" (low frequency/high strain magnitudes positions including quarterbacks, wide receivers, and defensive backs), "Profile 2" (mid-range impact frequency and strain positions including linebackers, running backs, and tight ends), and "Profile 3" (high frequency/low strains positions including defensive and offensive linemen). There were significant increases in GFAP 39.3 to 45.6 pg/mL and NF-L 3.5 to 5.4 pg/mL over the course of the season (p < 0.001) despite only five players being diagnosed with concussion. UCH-L1 decreased significantly, and Tau was not significantly different. In both the pre- and post-season blood samples Tau and NF-L concentrations were significantly higher in speed versus non-speed positions. Concentrations of GFAP, Tau, and NF-L increased incrementally from "Profile 3," to "Profile 2" to "Profile 1" in the post-season. UCH-L1 did not. GFAP increased (by Profiles 3, 2, 1) from 42.4 to 49.6 to 78.2, respectively (p = 0.051). Tau increased from 0.37 to 0.61 to 0.67, respectively (p = 0.024). NF-L increased from 3.5 to 4.9 to 8.2, respectively (p < 0.001). Although GFAP and Tau showed similar patterns of elevations by profile in the pre-season samples they were not statistically significant. Only NF-L showed significant differences between profiles 2.7 to 3.1 to 4.2 in the pre-season (p = 0.042). GFAP, Tau, and NF-L concentrations were significantly associated with different playing positions with the highest concentrations in speed and "Profile 1" positions and the lowest concentrations were in non-speed and "Profile 3" positions. Blood-based biomarkers (GFAP, Tau, NF-L) provide an additional layer of injury quantification that could contribute to a better understanding of the risks of playing different positions.

Association Between Head Impact Biomechanics and Physical Load in College Football.

Head impacts and physical exertion are ubiquitous in American football, but the relationship between these factors is poorly understood across a competitive season or even within an individual session. Gameplay characteristics, including player position and session type, may contribute to these relationships but have not been prospectively examined. The current study aimed to determine if an association exists between head impact biomechanics and physical load metrics. We prospectively studied college football players during the 2017–2021 football seasons across representative playing positions (15 offensive and defensive linemen, 11 linebackers and tight ends, and 15 defensive backs, running backs, and receivers). Participants wore halters embedded with Catapult Vector GPS monitoring systems to quantify player load and participant helmets were equipped with the Head Impact Telemetry System to quantify head impact biomechanics and repetitive head impact exposure (RHIE). Generalized linear models and linear regression models were employed to analyze in-session and season-long outcomes, while addressing factors such as player position and session type on our data. Player load was associated with RHIE (p < 0.001). Season-long player load predicted season-long RHIE (R2 = 0.31; p < 0.001). Position group affected in-session player load (p = 0.025). Both player load and RHIE were greater in games than in practices (p < 0.001), and position group did not affect RHIE (p = 0.343). Physical load burden was associated with RHIE within sessions and across an entire season. Session type affected both RHIE and player load, while position group only affected player load. Our data point to tracking physical load burden as a potential proxy for monitoring anticipated RHIE during the season.

Return to Play and Performance After Anterior Cruciate Ligament Reconstruction in National Football League Players.

Background:Considerable variability exists in return-to-play rates after anterior cruciate ligament (ACL) injury and reconstruction (ACLR) among National Football League (NFL) players of different positions.Purpose/Hypothesis:The purpose of this study was to compare return-to-play and performance levels by position in NFL players after ACLR. It was hypothesized that (1) ACL injuries have significant effects on the careers of NFL players, including return to play and performance, and (2) players of certain positions that involve relatively less pivoting and cutting perform better after ACLR.Study Design:Descriptive epidemiology study.Methods:All NFL players who underwent ACLR between 2013 and 2018 were identified using the FantasyData injury database. Player characteristics, snap count, games played, games started, and performance metrics were collected for 3 years before and after injury using the Pro Football Reference database. Performance was measured using an approximate value (AV) algorithm to compare performance across positions and over time. Nonparametric tests were used to compare the pre- and postinjury data and the percentage change in performance between different positions.Results:Overall, 312 NFL players were included in this study, and 174 (55.8%) returned to play. Of the eligible players, only 28.5% (n = 59/207) remained in the league 3 years postinjury. Within the first 3 years postinjury, players played in fewer games (8.7 vs 13.7; P < .0001), started in fewer games (3.0 vs 8.3; P < .0001), had lower AVs (1.5 vs 4.3; P < .0001), and had decreased snap counts (259.0 vs 619.0; P < .0001) compared with preinjury. Quarterbacks were most likely to return to play (92.9% vs 53.7%; P = .0040) and to return to performance (2% vs 50% decrease in AV; P = .0165) compared with the other positions. Running backs had the largest decrease in AV (90.5%), followed by defensive linemen (76.2%) and linebackers (62.5%).Conclusion:The study findings indicated that NFL players are severely affected by ACL injury, with only 28.5% still active in the league 3 years after the injury. Running backs, defensive linemen, and linebackers performed the worst after injury. Quarterbacks were most likely to return to play and had superior postinjury performance compared with the other positions.

Treatment Outcomes in American Football Players After Intervertebral Disk Herniation: Systematic Review and Meta-Analysis.

American football players are at increased risk for many forms of spinal injury. Intervertebral disk herniations are particularly concerning as they are the leading cause of days lost to injury and can have long-term effects on player careers. Disk herniation management plays a major role in the likelihood and success of return-to-play (RTP). To assess the incidence, demographic variables, treatment approaches, outcomes, and RTP rates of disk herniations in American football players. A systematic review of the literature investigating disk herniations in American football players using PubMed, Cochrane Library, and Embase was performed. RTP estimates were calculated by pooling study-specific data using a random-effects model. Four hundred twenty-two studies were identified, with 18 meeting inclusion criteria. Offensive and defensive linemen were the 2 most commonly injured positions. Players undergoing operations were on average younger, with higher body mass indexes, fewer seasons played, and longer post-treatment careers than nonsurgical counterparts. Postsurgical recovery periods lasted an average 106 d, with a mean RTP duration of 33 games over 2.7 yr and an 8.45% reoperation rate. Operative treatment offered a nonsignificant increase in the likelihood of return-to-play compared with nonoperative treatment (odds ratio = 2.81, 95% CI 0.83-9.51). Disk herniations are a common injury, with surgery potentially improving post-treatment outcomes. The literature suffers from heterogeneous definitions of RTP and varying performance metrics, making it difficult to draw clear conclusions. To better understand the impact of disk herniation and treatment on player health and performance, more studies should be performed prospectively and with standardized metrics.

Laboratory Evaluation of Shell Add-On Products for American Football Helmets for Professional Linemen.

The Guardian Cap NXT (GC NXT) and the ProTech Helmet Cap (ProTech) are commercially available aftermarket products designed to augment the energy attenuation characteristics of American football helmets. The ability of these helmet shell add-on products to mitigate the severity of impacts typically experienced by professional offensive and defensive linemen was evaluated for seven helmet models using two test series. In linear impactor tests, the GC NXT reduced head impact severity as measured by the head acceleration response metric (HARM) by 9% relative to the helmets only, while the ProTech reduced HARM by 5%. While both products significantly improved the performance of the football helmets tested overall, effects varied by impact condition and helmet model with the add-ons worsening helmet performance in some conditions. The GC NXT had a strong effect size (Cohen's d = 0.8) whereas the ProTech had a medium effect (Cohen's d = 0.5). A second study investigated add-on performance for helmet-to-helmet impacts with eccentric impact vectors and resulted in a mixture of increased and decreased HARM when either add-on was placed on one or both helmets. Estimated risk for serious neck injury with add-ons and without differed by less than 4% for these eccentric impacts.

Abdominal Adiposity in Collegiate Football Linemen: A Study of Race and Position.

American football linemen are at an increased risk for developing obesity-related diseases. This study evaluated the impact of race and position on abdominal fat (visceral adipose tissue and android fat percentage) in football linemen. Thirty-four offensive and defensive linemen (%fat: 27.1±7.2%) completed a total body dual-energy X-ray absorptiometry scan to estimate visceral fat and android fat percentage. Participants were stratified by race [Black: n=23; White: n=11] and position (Offense: n=18; Defense: n=16). Two separate two-way ANOVA tests [race × position] were completed. For visceral adipose tissue, there was no interaction (p=0.056), but there was an effect of race (Black: 0.57±0.34 kg; White: 1.51±0.56 kg; p <0.001) and position (Offense: 1.22±0.60 kg; Defense: 0.49±0.34 kg; p<0.001). For android fat percentage, there was no interaction (p=0.855) or race effect (Black: 31.5±11.3%; White: 40.9±8.6%; p=0.123); there was a position effect (Offense: 42.1±5.6%; Defense: 26.0±9.9%; p<0.001). Offensive linemen, regardless of race, had greater visceral adipose tissue and android fat percent compared to defensive linemen. White linemen had greater visceral adipose tissue, regardless of position. These results suggest football linemen, especially offensive linemen with increased abdominal adiposity, may benefit from tracking metabolic health during their collegiate career to mitigate obesity-related disease risk once retired from sport.

Performance and Survivorship of National Football League Players with Pectoralis Major Injuries

PurposeThe purpose of this study was to determine return-to-play (RTP), performance and career survivorship for National Football League (NFL) athletes sustaining pectoralis major (PM) injuries with comparison among grades of injury and between nonoperative and operative management.MethodsPublicly available data from the 1998–2020 NFL seasons were reviewed to identify athletes with PM injuries. Athlete characteristics were collected 1 season before and 2 seasons after injury. Percent of total games played in a season, player efficiency rating (PER), and Pro Football Focus (PFF) grades were compared for the preinjury season and 2 postinjury seasons. Kaplan-Meier survivorship plots were computed for RTP and postinjury career length, whereas a log-rank test was used to compare survivorship differences.ResultsIn total, 258 PM injuries were reported at a mean age of 27.1 ± 3.3 years. A total of 126 surgical repairs occurred in 48.8% (n = 126) of injuries, with athletes undergoing repair possessing a lower RTP rate and longer time to RTP compared to athletes treated conservatively (P < .001). Survival analysis revealed shorter career length for athletes sustaining PM tears compared to strains (P < .001), although no difference in career length was appreciated on the basis of injury management (P = .980). Defensive linemen and wide receivers had lower PER during their second postinjury seasons (P = .019 and .030, respectively), whereas defensive linemen had lower PFF grades during their second post-injury seasons (P = .044).ConclusionNFL athletes requiring PM repair may experience a lower likelihood of RTP, and longer RTP timing, likely because of higher-grade injuries. Defensive linemen and wide receivers experiencing PM injuries are at risk for diminished performance post-injury. Career length does not appear to be affected based on injury management.Level of EvidenceLevel III, cohort study.