scholarly journals Positional Differences in Pre-Season Scrimmage Performance of Division I Collegiate Football Players

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 769
Author(s):  
Kate S. Early ◽  
Nathan P. Lemoine ◽  
Annie Simoneaux ◽  
Shelly Mullenix ◽  
Jack Marucci ◽  
...  

This study aimed to describe the physical demands of American football players using novel performance analysis techniques. Heart rate (HR) and accelerometer-based activity levels were observed across two pre-season scrimmages in 23 Division I collegiate football players (age: 19 ± 1 y, height: 1.90 ± 0.06 m, weight: 116.2 ± 19.4 kg). Data were analyzed using a MATLAB program and inter-rater reproducibility assessed using inter-class correlations (ICC). Players were analyzed by side (offense/defense) and position (skill/non-skill). Performance variables assessed in bursts of activity included burst duration, HRmean and HRmax (bpm), and mean activity (vector magnitude units [vmu]). Exercise intensity was categorized as time spent in % HRmax in 5% increments. The burst duration (8.1±3.9 min, ICC = 0.72), HRmean (157 ± 12 bpm, ICC = 0.96) and mean activity (0.30 ± 0.05 vmu, ICC = 0.86) were reproducible. HRmean (p = 0.05) and HRmax (p = 0.001) were greater on defense. Offense spent more time at 65–70% HRmax (p = 0.01), 70–75% HRmax (p = 0.02) while defense spent more time 90–95% HRmax and ≥95% HRmax (p = 0.03). HRmean (p = 0.70) and HRpeak (p = 0.80) were not different between positions across both sides. Skilled players demonstrated greater mean activity (p = 0.02). The sport-specific analysis described HR and activity level in a reproducible manner. Automated methods of assessing HR may be useful in training and game time performance but ultimately provides support to coaching decision making.

Author(s):  
Rebecca M. Hirschhorn ◽  
Jessica L. Phillips Gilbert ◽  
Danielle A. Cadet ◽  
Tenley E. Murphy ◽  
Clinton Haggard ◽  
...  

American football athletes are frequently hypohydrated before and during activity. Hypohydration increases the risk of exertional sickling in student-athletes with sickle cell trait (SCT). The authors examined weight charts from the 2010/2011 to 2018/2019 seasons at one Division I institution to determine if differences in percentage body mass losses (%BML) exist between those with and without SCT. Seventeen student-athletes with SCT and 17 matched-controls were included. A Bonferroni correction was applied to account for multiple comparisons (0.05/8), resulting in p < .006 considered significant. There was a significant difference for %BML between groups (SCT: 0.84 ± 0.65% vs. control: 1.21 ± 0.71%; p = .002) but not for the number of days %BML exceeded 2% (SCT: 0 ± 1 vs. control: 1 ± 1; p = .016). Implementation of proper hydration strategies minimized %BML in athletes with SCT, decreasing the risk of hypohydration and exertional sickling. The same strategies ensured all players remained below threshold to optimize performance and reduce heat illness risk.


Author(s):  
Laura D Wilson ◽  
Rachel A Hildebrand ◽  
Trang Le ◽  
Brett A McKinney

This study describes exposure to repetitive head impacts (RHI) by player position and activity during a collegiate football season, and investigates the relationship between RHI and acute (i.e., daily and weekly) and short-term (i.e., pre- to post-season) changes in balance, reaction time, symptoms, and cognition. We recorded RHI exposure in twenty Division I collegiate American football players during a single season using the Riddell InSite system. Participants sustained 4,586 impacts (4.20% high impact, i.e., >63 g; 95.79% low impact, i.e., 20–63 g). Greatest exposure to RHI was observed in running backs and defensive ends during games, and tight ends and defensive ends during practices. Running plays and team drills placed players at greatest risk for exposure during practice. Cumulative RHI exposure across the season was associated with short-term declines in reaction time (p = 0.045), but not balance or cognition. Acute decline in balance was associated with the number of impacts sustained in the past week (p < 0.05), but not the past 24 hours (p > 0.05). Acute increase in total symptom score was also associated with the number of impacts sustained in the past week (p < 0.01), but not the past 24 hours (p > 0.05). Reaction time did not decline based on impact exposure in the past 24 hours or week. This study identifies activities and positions that may put players at risk for RHI exposure, and demonstrates that RHI sustained during the course of typical American football play by non-concussed individuals may result in small changes in balance, reaction time, and symptoms, but not cognition.


2019 ◽  
Vol 11 (4) ◽  
pp. 332-342 ◽  
Author(s):  
Benjamin L. Brett ◽  
Daniel L. Huber ◽  
Alexa Wild ◽  
Lindsay D. Nelson ◽  
Michael A. McCrea

Background: Although some studies have observed a relationship between age of first exposure (AFE) to American football and long-term outcomes, recent findings in collegiate athletes did not observe a relationship between AFE and more intermediate outcomes at early adulthood. This, however, requires independent replication. Hypothesis: There will be no association between AFE to football and behavioral, cognitive, emotional/psychological, and physical functioning in high school and collegiate athletes. Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: Active high school and collegiate football players (N = 1802) underwent a comprehensive preseason evaluation on several clinical outcome measures. Demographic and health variables that significantly differed across AFE groups were identified as potential covariates. General linear models (GLMs) with AFE as the independent variable were performed for each clinical outcome variable. Similar GLMs that included identified covariates, with AFE as the predictor, were subsequently performed for each clinical outcome variable. Results: After controlling for covariates of age, concussion history, race, and a diagnosis of ADHD, earlier AFE (<12 vs ≥12 years) did not significantly predict poorer performance on any clinical outcome measures (all P > 0.05). A single statistically significant association between AFE group and somatization score was recorded, with AFE <12 years exhibiting lower levels of somatization. Conclusion: In a large cohort of active high school and collegiate football student-athletes, AFE before the age of 12 years was not associated with worse behavioral, cognitive, psychological, and physical (oculomotor functioning and postural stability) outcomes. Clinical Relevance The current findings suggest that timing of onset of football exposure does not result in poorer functioning in adolescence and young adults and may contribute to resilience through decreased levels of physically related psychological distress.


2017 ◽  
Vol 12 (9) ◽  
pp. 1264-1266 ◽  
Author(s):  
Hugh H.K. Fullagar ◽  
Andrew Govus ◽  
James Hanisch ◽  
Andrew Murray

Purpose:To investigate the recovery time course of customized wellness markers (sleep, soreness, energy, and overall wellness) in response to match play in American Division I-A college football players. Methods:A retrospective research design was used. Wellness data were collected and analyzed for 2 American college football seasons. Perceptions of soreness, sleep, energy, and overall wellness were obtained for the day before each game (GD–1) and the days after each game (GD+2, GD+3, and GD+4). Standardized effect-size (ES) analyses ± 90% confidence intervals were used to interpret the magnitude of the mean differences between all time points for the start, middle, and finish of the season, using the following qualitative descriptors: 0–0.19 trivial, 0.2–0.59 small, 0.6–1.19 moderate, 1.2–1.99 large, <2.0 very large. Results:Overall wellness showed small ES reductions on GD+2 (d = 0.22 ± 0.09, likely [94.8%]), GD+3 (d = 0.37 ± 0.15, very likely), and GD+4 (d = 0.29 ± 0.12, very likely) compared with GD–1. There were small ES reductions for soreness between GD–1 and GD+2, GD+3, and GD +4 (d = 0.21 ± 0.09, likely, d = 0.29 ± 0.12, very likely, and 0.30 ± 0.12, very likely, respectively). Small ES reductions were also evident between GD–1 and GD+3 (d = 0.21 ± 0.09, likely) for sleep. Feelings of energy showed small ESs on GD+3 (d = 0.27 ± 0.11, very likely) and GD+4 (d = 0.22 ± 0.09, likely) compared with GD–1. Conclusion:All wellness markers were likely to very likely worse on GD+3 and GD+4 than on GD–1. These findings show that perceptual wellness takes longer than 4 d to return to pregame levels and thus should be considered when prescribing training and/or recovery.


Sports ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 165
Author(s):  
Eric J. Sobolewski

The aim of this study is to explore the relationships between internal and external load measures in American football. Thirty football players wore a portable integrated monitor unit for 10 weeks during the fall football season. Relationships between internal and external load measurements were determined. Internal load consisted of heart rate zones and heart rate-derived measures and session Ratings of Perceived Exertion (sRPE). External load consisted of distance in different speed zones, total distance traveled, and accelerations. There were many significant positive relationships, but the meaningful relationships (r > 0.5) were between heart rate-derived measures of load (Training Impulse and heart rate reserve) and low-intensity movement and total distance. Only accelerations between 1 and 1.99 m·s−2 were moderately correlated to heart rate-derived internal load. RPE values alone did not correlate strong enough with any of the measure but sRPE training load (sRPE-TL) correlated to most external values. Overall, moderate correlations were present between heart rate-derived internal load to total distance and lower intensity movement. sRPE-TL values had high correlations but were highly dependent on duration, not perceived exertion. When addressing load in American football, duration of the session is a key component in determining internal load as HR data and sRPE alone do not correlate highly with external loads.


2013 ◽  
Vol 48 (6) ◽  
pp. 818-825 ◽  
Author(s):  
Junta Iguchi ◽  
Yosuke Yamada ◽  
Misaka Kimura ◽  
Yoshihiko Fujisawa ◽  
Tatsuya Hojo ◽  
...  

Context: Previous research on American football injuries in Japan has focused on incidence proportion in terms of the number of injuries divided by the number of players. This is the first study to examine injury rates over several seasons. Objective: To conduct a prospective study of injuries in a Japanese Division I collegiate American football team over the 2007 through 2009 seasons. Design: Cohort study. Setting: Collegiate football team at Doshisha University, Kyoto, Japan. Patients or Other Participants: All 289 athletes who played on the collegiate Division I football team during the 2007 through 2009 seasons. Main Outcome Measure(s): A certified athletic trainer kept a daily record of all practice and game injuries. Injury rates were calculated according to season, injury type, body part, severity, and mechanism. Injuries were also analyzed according to position of player, school year, and playing experience. Results: The game injury rate (GIR; 32.7 injuries/1000 athlete-exposures) was higher than the practice injury rate (PIR; 10.9 injuries/1000 athlete-exposures) over the 3 seasons (P &lt; .05). The PIR was higher among Japanese players than the comparable United States collegiate football injury rates (5.8–7.0 injuries/1000 athlete-exposures). Ankle and foot injuries occurred more frequently during games, whereas thigh and gluteal injuries occurred more frequently during practices. Conclusions: Our data show differences between games and practices in terms of injury rates, body parts injured, and positions of players injured. The high PIR in Japan may be due to the increased contact during practices and length of practices compared with the United States. Further research involving multiple teams is recommended to validate the trends noted in this study. The expanded data set could assist in the development of safety regulations and preventive interventions for Japanese football.


2015 ◽  
Vol 32 (5) ◽  
pp. 314-326 ◽  
Author(s):  
Christine M. Baugh ◽  
Patrick T. Kiernan ◽  
Emily Kroshus ◽  
Daniel H. Daneshvar ◽  
Philip H. Montenigro ◽  
...  

2017 ◽  
Vol 45 (4) ◽  
pp. 458-462 ◽  
Author(s):  
Nikolas Sarac ◽  
William Haynes ◽  
Angela Pedroza ◽  
Christopher Kaeding ◽  
James Borchers

2019 ◽  
Vol 54 (9) ◽  
pp. 929-938 ◽  
Author(s):  
Daniel L. Huber ◽  
Danny G. Thomas ◽  
Michael Danduran ◽  
Timothy B. Meier ◽  
Michael A. McCrea ◽  
...  

Context Interest in identifying the effects of physical and mental activity on recovery after sport-related concussion is growing. Clinical studies of concussed athletes' activities require well-validated methods for tracking their intensity and timing. Objective To develop and validate a novel multimodal approach to monitoring activity postconcussion using mobile (mHealth) technologies. Design Cohort study. Setting Translational research unit. Patients or Other Participants A total of 40 high school and collegiate football players were evaluated at preseason and followed longitudinally after either concussion (n = 25; age = 17.88 ± 1.74 years, height = 182.07 ± 8.08 cm, mass = 98.36 ± 21.70 kg) or selection as a nonconcussed control (n = 15; age = 18.27 ± 1.83 years, height = 180.01 ± 7.19 cm, mass = 93.83 ± 24.56 kg). Main Outcome Measure(s) Participants wore a commercial actigraph and completed a daily mobile survey for 2 weeks. Analyses focused on comparisons between groups for actigraph-based physical activity and self-reported physical and mental activity during the follow-up period. Results For the first 2 days postinjury, objective measures showed fewer daily steps in concussed (6663 ± 2667 steps) than in control (11 148 ± 3381 steps) athletes (P &lt; .001), and both objective and self-reported measures indicated less moderate to vigorous physical activity in concussed (27.6 ± 32.6 min/d and 25.0 ± 43.6 min/d, respectively) than in control (57.3 ± 38.6 min/d and 67.5 ± 40.1 min/d, respectively) athletes (both P values &lt; .05). Correlations between objective and self-reported measures of moderate to vigorous physical activity were moderate across select 1-week and 2-week averages. We observed no group differences in self-reported mental activities. Conclusions Physical activity after sport-related concussion varied widely across athletes but on average was reduced during the acute and early subacute postinjury periods for both objective and self-reported measures. The lack of differences in mental activities between groups may reflect limited change in mental exertion postconcussion or difficulty accurately measuring mental activities. Assessing concussed athletes' activities using actigraphy and self-reported scales may help monitor their compliance with activity recommendations and be useful in studies aimed at better understanding the effects of physical activity on concussion recovery.


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