Data from: Effects of repetitive head impacts from a single season on the cognitive functioning of youth male soccer players
Data files
May 05, 2026 version files 472.44 KB
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README.md
4.03 KB
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Revised_Manuscript_CMI_Data.xlsx
399.72 KB
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Revised_Manuscript_Head_Impact_Data_.xlsx
68.69 KB
Abstract
Repetitive head impacts have long-lasting negative effects on the cognition of athletes. For example, repetitive head impacts accumulated by adult professional soccer players throughout their careers result in long-term negative consequences on cognition. However, these effects on youth soccer players have not been extensively studied and need to be further evaluated. The purposes of this study were to quantify head impact exposure in youth elite soccer and to examine the effects of repetitive head impacts on the cognitive function of youth male soccer players. A prospective cohort study of a single boys U13 soccer team of 18 players (12.9 ± 0.2 years of age) was completed throughout a single soccer season (five months in duration). Head impact frequency data were recorded using impact monitoring mouthguards worn during practices and games and subsequently video-verified. Cognitive function was assessed using cognitive-motor integration (CMI) tasks conducted before the first season game, every subsequent four weeks, and after the last game. Peak path velocity, absolute error, reaction time, full path movement time, and the number of direction reversals were CMI task outcome measures. Over a single soccer season, 1089 head impacts occurred with more head impacts occurring in practices (62.7%) than in games (37.3%). Midfielders experienced the most head impacts during practices (53.6% of practice impacts), and defenders experienced the most head impacts during games (47.8% of game impacts). Repetitive head impact exposure by position was associated with significant decreases in absolute error (p<0.001), increases in peak velocity (p<0.001), and increases in reaction time (p<0.001). Repetitive head impacts within a single soccer season were associated with measurable declines in some aspects of youth soccer players’ cognitive function. Therefore, coaches should aim to reduce the number of head impacts experienced by male youth soccer players with a specific focus on reducing head impact exposure during practices.
Dataset DOI: 10.5061/dryad.wm37pvn05
Description of the data and file structure
Observational data were collected to quantify the number of head impacts experienced within a soccer season by youth athletes. Head impacts were described by player position and by game scenario for games and practices throughout the soccer season.
Cognitive motor integration tasks were conducted to evaluate the effect of repetitive head impacts on the player's cognitive function throughout a soccer season. Cognitive motor integration tasks were completed six times throughout the season.
Files and variables
File: Revised_Manuscript_CMI_Data.xlsx
Description: Five outcome measures from each trial of the CMI tasks were used to assess cognitive function: peak finger velocity, absolute error, reaction time, full path movement time, and direction reversal errors. The raw data were processed, and these five outcome measures were extracted for each trial in all CMI tasks. The file includes the successful trials, all trials that were removed due to error, the number of direction reversals that occurred for each trial, and the corresponding head impact data.
Variables
- Condition = Which of the four CMI test conditions did the direction reversal occur on
- trial_nr= trial number (which of the 20 trials for each of the 4 conditions)
- RT = Reaction time (milliseconds; ms)
- MT_fullpath= Full path movement time (milliseconds; ms)
- AbsErr= Absolute Error (distance between the average initial movement endpoint for each target location and the actual target position)
- Peak_vel_all= Peak Velocity (millimetres/ millisecond; mm/ms)
- cum_impacts= Cumulative head impacts at time of test
- trial_outcome= error code (code 3-6= technical errors, 7= Trial deleted by researcher (unusable data))
- Test = CMI Testing Session
- nrDR = Number of direction reversals required for the cursor to reach the correct target
File: Revised_Manuscript_Head_Impact_Data_.xlsx
Description: The file includes head impact data by player position and game scenario, as well as participant attendance and demographic information.
Variables
- Player position (1 = Forward, 2 = Midfield, 3 = Defence; 4 = Goalie)
- Head impact event type (1 = Player to Player, 2= Player to Ground; 3 = Player to Ball; 4= Indirect, 5 = Other)
- Type of header ( 1= Directional Header; 2 = Standard Header; 3 = Flick Header; 4 = Diving Header; 5 = Jumping Header; 6 = Unexpected Header; 7 = Other)
- If Header/Ball Impact, Originated from what scenario ( 1 = Corner Kick; 2 = Drop Kick, 3 = Defensive Clearing Kick; 4 = Free Kick; 5 = Goal Kick; 6 = Shot; 7 = Pass in Air; 8 = Ball Deflection from ground; 9 = Ball Deflection from Player or Object; 10= throw in, 11= goalie dive, 12= other)
- Event type (1= Practice, 2= Game, 3= Tournament)
- IMM = Impact monitoring mouthguard
- CMI == Cognitive motor integration (the task used to assess cognitive function)
- IMMV nVV game = Impact monitoring mouthguard-verified, non-video verified game head impact
- IMMv VV game = Impact monitoring mouthguard-verified, video-verified game head impact
- VV nIMMv Game = video-verified, non-impact monitoring mouthguard-verified game head impact
- nVV nIMMv game= non-video-verified, non-impact monitoring mouthguard-verified game headimpactt
- IMMpractice =e= Impact monitoring mouthguard-verified practice head impact
- nIMpractice = ce = non-impact monitoring mouthguard-verified practice head impact
Code/software
Microsoft Excel is required to view the data.
Human subjects data
Informed written assent from participants and informed written consent from their legal guardians was received to publish de-identified data in the public domain. Any identifying information was removed and all participants were given a unique participant ID code.