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Concept: Canadian football

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The aim of this study was to determine the changes in anthropomorphism and performance over a four year eligibility career of American football players. A total of 92 offensive and defensive linemen and 64 skill (wide receivers and defensive backs) player observations were included in the analysis. Data from pre-season testing over a seven year period were compiled, sorted and analyzed by players' year in school. Assessments of strength included 1RM bench press, squat, power clean and a 225 lb. maximum repetition muscle endurance test. Power and speed measures included the vertical jump (VJ) and 40 yd (36.6m) sprint. All strength measures improved significantly (p<0.05) over the years of training. Skill players demonstrated a significant increase in power (W) between years 1 and 2, but at no other time. Linemen did not demonstrate significant changes in VJ. Speed did not change significantly for either group over the four years of training. These data provide a theoretically predictable four-year rate of change in anthropometric, strength and power variables for Division I football players. By having a longitudinal assessment of expected physical improvement it may be possible for strength training personnel to determine those who may need additional attention in an area in order to more closely improve as expected. Additionally, it is suggested that elite athletes may possess genetically superior attributes and therefore, when selecting athletes particular attention should be paid to the selection of those who have previously demonstrated superior speed and power.

Concepts: Better, Improve, College football, American football, Division I, Canadian football, American football positions, Cornerback

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The purpose of this study was to document changes in height (cm), body weight (kg) and body composition (%fat) of American football players from 1942 to 2011. Published articles were identified from data bases and cross referencing of bibliographies. Studies selected met the requirements of: 1) having two of three dependent (height, body weight, and body composition) variables reported in the results; 2) containing a skill level of college or professional; 3) providing measured, not self-reported data; and 4) published studies in English-language journals. The data were categorized into groups based on skill level (college and professional). The player positions were grouped into three categories: mixed linemen (offensive and defensive linemen, tight ends, and linebackers), mixed offensive backs (quarterback, and running backs), and mixed skilled positions (defensive backs and wide receivers). Linear regression was used to provide slope estimates and 95% confidence intervals. Unpaired t-tests were used to determine whether an individual regression slope was significantly different from zero. Statistical significance was set at p < 0.017. College level players in all position groups have significantly increased body weight over time (95% CI mixed lineman .338-.900 kg/yr; mixed offensive backs .089-.298 kg/yr; mixed skilled .078-.334 kg/yr). The college level mixed linemen showed a significant increase over time for height (95% CI .034-.188 cm/yr) and body composition (.046-.275 %fat/year). Significant increases in body weight over time were found for professional level mixed lineman (95% CI .098-.756 kg/yr) and mixed offensive backs (95% CI .180-.545 kg/yr). There were no other significant changes at the professional level. These data demonstrate that body weight of all college players and professional mixed lineman have significantly increased from 1942 to 2011.

Concepts: Statistics, Statistical hypothesis testing, American football, Football, Canadian football, American football positions, Tight end, Fullback

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There is limited information on the relationship between football helmet fit and concussion severity.

Concepts: High school, Texas, American football, High School Musical, High school football, Canadian football, Columbus, Ohio

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The aims of the present study were to 1) examine positional impact profiles of NCAA division I college football players using global positioning system (GPS) and integrated accelerometry (IA) technology, and 2) determine if positional differences in impact profiles during competition exist within offensive and defensive teams. Thirty-three NCAA Division I Football Bowl Subdivision players were monitored using GPS and IA (GPSports, Canberra, Australia) during 12 regular season games throughout the 2014 season. Individual player datasets (n = 294) were divided into offensive and defensive teams, and positional sub-groups. The intensity, number, and distribution of impact forces experienced by players during competition were recorded. Positional differences were found for the distribution of impacts within offensive and defensive teams. Wide receivers (WR) sustained more very light and light to moderate (5-6.5 G force) impacts than other position groups, while the running backs (RB) were involved in more severe (>10 G force) impacts than all offensive position groups, with the exception of the quarterbacks (QB) (p<0.05). The defensive back (DB) and linebacker (LB) groups were subject to more very light (5.0-6.0 G force) impacts, and the defensive tackle (DT) group sustained more heavy and very heavy (7.1-10 G force) impacts than other defensive positions (p<0.05). Data from the present study provide novel quantification of positional impact profiles related to the physical demands of college football games and highlight the need for position-specific monitoring and training in the preparation for the impact loads experienced during NCAA Division I football competition.

Concepts: College football, Global Positioning System, American football, Division I, National Collegiate Athletic Association, Canadian football, American football positions, NCAA Division I Football Championship

1

Teramoto, M, Cross, CL, and Willick, SE. Predictive value of National Football League scouting combine on future performance of running backs and wide receivers. J Strength Cond Res 30(5): 1379-1390, 2016-The National Football League (NFL) Scouting Combine is held each year before the NFL Draft to measure athletic abilities and football skills of college football players. Although the NFL Scouting Combine can provide the NFL teams with an opportunity to evaluate college players for the upcoming NFL Draft, its value for predicting future success of players has been questioned. This study examined whether the NFL Combine measures can predict future performance of running backs (RBs) and wide receivers (WRs) in the NFL. We analyzed the 2000-09 Combine data of RBs (N = 276) and WRs (N = 447) and their on-field performance for the first 3 years after the draft and over their entire careers in the NFL, using correlation and regression analyses, along with a principal component analysis (PCA). The results of the analyses showed that, after accounting for the number of games played, draft position, height (HT), and weight (WT), the time on 10-yard dash was the most important predictor of rushing yards per attempt of the first 3 years (p = 0.002) and of the careers (p < 0.001) in RBs. For WRs, vertical jump was found to be significantly associated with receiving yards per reception of the first 3 years (p = 0.001) and of the careers (p = 0.004) in the NFL, after adjusting for the covariates above. Furthermore, HT was most important in predicting future performance of WRs. The analyses also revealed that the 8 athletic drills in the Combine seemed to have construct validity. It seems that the NFL Scouting Combine has some value for predicting future performance of RBs and WRs in the NFL.

Concepts: Regression analysis, Prediction, Futurology, American football, National Football League, Canadian football, American football positions, Lucas Oil Stadium

1

While there have been investigations into the reduced neck injury rate of wearing protective helmets, there is little information on its effects on normal kinaesthetic neck function. This study aims to quantify the kinaesthetic and movement effects of the American football helmet.

Concepts: United States, American football, Helmet, Helmets, Canadian football, Association football headgear, Lists of American football players, Football helmet

1

The session-rating of perceived exertion (Session-RPE) method for quantifying internal training load (TL) has proven to be a highly valuable and accurate monitoring tool in numerous team sports. However, the influence of frequent impact during Canadian football on the validity of on this subjective rating tool remains unclear. The aim of this study was to validate Session-RPE application to a prolonged intermittent high intensity collision-based team sport through correlation of internal TL data collected using two criterion heart rate-based measures known as Polar Training-Impulse (TRIMP) and Edwards' TL. Twenty male participants (age = 22.0±1.4 years) from the competitive roster of the University of Saskatchewan Canadian football team were recruited. Session-RPE, Polar TRIMP and Edward’s TL data were collected daily over the 2011 Canadian Interuniversity Sport pre- and competitive season (11 weeks; 713 total practice sessions). On average each player contributed 36 sessions of data to the analysis. Statistically significant correlations (p<0.01) between Session-RPE with Polar TRIMP (r range: 0.65-0.91) and with Edwards' TL (r range: 0.69-0.91) were found for all individual players. This study provides confirmation that Session-RPE is an inexpensive and simple tool which is highly practical and accurately measures an individual's response (internal TL) to Canadian football practice. Furthermore, when considering the number of individuals involved world-wide in collision-based team sports, this tool has the potential to impact a large proportion of the global sporting community.

Concepts: Statistics, Spearman's rank correlation coefficient, Pearson product-moment correlation coefficient, Canadian football, Canadian Football League, Team sports, Canadian Interuniversity Sport, Ball games

0

Reasons for Study: Sideline assessment tools are an important component of concussion evaluations. To date there has been little data evaluating the clinical utility of these tests in professional football. The purpose of this study was to evaluate the clinical utility of the King-Devick Test (KD) in evaluating concussions in professional football players. Baseline data was collected over 2 consecutive seasons in the Canadian Football League as part of a comprehensive medical baseline evaluation. A pilot study with the KD began in 2015 with 306 participants and the next year (2016) there were 917 participants. In addition, a sample of 64 participants completed testing after physical exertion (practice or game).

Concepts: Evaluation, Evaluation methods, Assessment, American football, Football, Canadian football, Canadian Football League, Professional sports

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The objective of this study was to assess the incidence of motor impairment in former professional Canadian Football League (ex-CFL) players with multiple concussions. We investigated motor symptoms and signs in 45 ex-CFL players with multiple concussions and 25 age-and education matched healthy controls with no history of concussion. Neurological assessment included items from the SCAT3 (Sport Concussion Assessment Tool 3) and the Unified Parkinson’s Disease Rating Scale part III (UPDRS-Part III). A performance-based measurement of manual motor function was undertaken using the Grooved Pegboard test. Cognition was measured with patient-reported outcomes for memory, executive and behavioral symptoms as well as performance-based measures of memory and executive function. Symptoms of anxiety and depression were measured using the Personality Assessment Inventory. There was no significant difference between the ex-CFL players and controls on the UPDRS-Part III scores, and neither group reported clinically significant motor complaints. Ex-CFL players did not perform differently from control subjects on the Grooved Pegboard test. In contrast, with regard to cognitive and mood testing, players were more symptomatic: The ex-CFL players reported significantly more memory (77.8% vs. 16%, respectively, p<0.001), executive (53.3% vs. 8%, respectively, p<0.001), and behavioral symptoms (66.7% vs. 20%, respectively, p<0.001). No significant differences were found when comparing ex-CFL players and controls in performance on memory and executive tests. In summary, in a group of retired CFL players who self-reported declines in memory, executive and behavioral symptoms, no motor symptoms were reported and no motor signs were detected.

Concepts: Psychology, Statistical significance, Parkinson's disease, Psychometrics, Unified Parkinson's Disease Rating Scale, American football, Canadian football, Canadian Football League

0

The 505 involves a 10-m sprint past a timing gate, followed by a 180° change-of-direction (COD) performed over 5 m. This methodological report investigated an adapted 505 (A505) designed to be football-specific by changing the distances to 10 and 5 yd. Twenty-five high school football players (6 linemen [LM]; 8 quarterbacks, running backs, and linebackers [QB/RB/LB]; 11 receivers and defensive backs [R/DB]) completed the A505 and 40-yd sprint. The difference between A505 and 0-10 yd time determined the COD deficit for each leg. In a follow-up session, 10 subjects completed the A505 again, while 10 subjects completed the 505. Reliability was analyzed by t-tests to determine between-session differences, typical error (TE), and coefficient of variation (CV). Test usefulness was examined via TE and smallest worthwhile change (SWC) differences. Pearson’s correlations calculated relationships between the A505 and 505, and A505 and COD deficit with the 40-yd sprint. A one-way ANOVA (p < 0.05) derived between-position differences in the A505 and COD deficit. There were no between-session differences for the A505 (p = 0.45-0.76; ICC = 0.84-0.95; TE = 2.03-4.13%). Additionally, the A505 was capable of detecting moderate performance changes (SWC0.5 > TE). The A505 correlated with the 505 and 40-yard sprint (r = 0.58-0.92), suggesting the modified version assessed similar qualities. R/DB were faster than LM in the A505 for both legs, and right-leg COD deficit. QB/RB/LB were faster than LM in the right-leg A505. The A505 is reliable, can detect moderate performance changes, and can discriminate between football position groups.

Concepts: Difference, Reliability, Change, American football, High school football, Canadian football, American football positions, Fullback