Data-informed Intervention Improves Football Technique and Reduces Head Impacts

Abstract

Introduction: Although sport participation is a key contributor to the physical and mental health of children and youth, exposure to subconcussive head impacts in football has raised concerns about safety for athletes.

Purpose: To demonstrate the efficacy of incorporating targeted football drills into a team's practice routine with the goal of improving players' technique and reduce exposure to subconcussive head impacts.

Methods: Seventy high school football players (age, 16.4 ± 1.1 yr) were tested PRE season using a sport-specific functional assessment. Results from the testing were used to inform the design of a prepractice intervention aimed at improving tackling and blocking techniques while reducing exposure to head impacts. The assessment included drills which evaluated the players' ability to safely tackle, and block while simulating game-like situations. Testing was repeated at MID season (internal control) without an intervention, and again at POST season (experimental), after introduction of the prepractice intervention between these timepoints, administered twice weekly. All testing sessions were recorded, and subsequently reviewed by trained graders based on selected criteria defined by football coaches. A subset of 19 participants wore in-helmet accelerometers to assess the effectiveness of the intervention in decreasing head impacts during practice.

Results: Significant improvements in blocking and tackling techniques were observed after the introduction of the intervention (P < 0.0001). Participating athletes also showed better techniques when evaluated in new game-like situations, postseason, providing evidence for proper acquisition and generalizability of these safer habits. Finally, frequency of head impacts (>15g) per practice was significantly reduced by ~30% after 1 month of training.

Conclusion: Our results suggest that data-informed methods can be used to improve coaching practices and promote safer play, which can have a positive public health impact moving forward.

FIGURE 1

Football-specific tackling and blocking drills used to assess the players’ technique throughout the season. Tackling drills 1 (A) and 2 (B), along with blocking drills 3 (C) and 4 (D) were repeated twice (one per side) at each data collection timepoint (PRE, MID, POST season). Tackling drill 5 (E) and blocking drill 6 (F) were used only at the POST season timepoint to assess the effectiveness in the intervention to translate proper skills to new game-like situations.

FIGURE 2

Schematic of experimental study design. The study design where players were tested PRE, MID, and POST seasons using the drills presented in Fig. 1. A biweekly (twice a week) data-informed team intervention (green) was introduced after the MID season testing session. Evaluated film clips from baseline performance were shared with all athletes and coaches, after the MID season testing (red). A subset of 19 athletes also wore helmet accelerometers (blue) 3 wk before, and 1 month after the MID season testing, to assess possible reduction in head impacts per practice.

FIGURE 3

Methodology for randomization and scoring of the footage acquired at each time point. The methodological approach used to score the movie clips while blinding the graders on the time point of interest. B, baseline testing, P, postseason testing.

FIGURE 4

Boxplot from post hoc results from statistical analysis of safety scores throughout the season. Boxplots for each time point in drill 1 (A), 2 (B), 3 (C) and 4 (D) showing the minimum, maximum, median (red) along with the interquartile range. Differences across time points were assessed using a linear mixed model for repeated measures, and post hoc pairwise comparisons, upon significant differences over time (*P < 0.05).

FIGURE 5

Results from tackling and blocking skill translation and generalizability assessments. (A, B) Statistical results from ANOVA between PRE season mean safety baseline scores and drill 5 (Fig. 1E) and 6 (Fig. 1F) postseason (*P < 0.05). (C, D) Case-studies from PRE and POST seasons assessment showing the improvement in the player’s technique for tackling (C) and blocking (D).