(D-122) Evaluating the relationship between tackling form and head kinematics in youth football

Introduction:: Introduction: Youth football has over 2.8 million participants between the ages of 6 and 13 each year.¹ Participation in football is not without risk and athlete safety is of increasing concern with particular interest surrounding athlete-to-athlete collisions.² A tackle is a foundational skill of football and must be properly executed to maximize the safety of all athletes involved in the collision. Improper tackling form influences head and neck injury risk and can lead to decreased performance.³ There is a critical gap in the influence of athlete form on head kinematics during a football tackle. The objective of this study was to develop a tackling form scoring rubric and evaluate the relationship between tackling form and head kinematics in a sample of youth football athletes.


Materials and Methods:: Materials and Methods: A tackling form scoring rubric was developed with guidance from an advisory team of football stakeholders (i.e., coaches of youth and high school football teams) and informed by current standards and guidelines for proper tackling.⁴ The rubric included the following steps: Stance, Approach, Contact, Head Placement, Wrap Up, and Follow Through. Each of the six steps had three sub-steps that were used to evaluate the athlete’s tackle form. Biomechanics data were collected from 14 athletes on a single youth football team using an instrumented mouthpiece during team practice sessions. On-field video of one-on-one tackling drills were captured perpendicular to contact.⁵ Four football experts (i.e., coaches) independently scored tackle events with each tackle event scored by two experts. A third independent reviewer resolved discrepancies across scores. Each tackle was categorized as successful (i.e., ball carrier’s forward progress was halted), or not successful (i.e., ball carrier continued forward). Peak resultant linear acceleration, rotational acceleration, and rotational velocity were calculated for each verified event.


Results, Conclusions, and Discussions:: Results and Discussion: A total of 127 tackle events were reviewed using the tackling form grading rubric across 9 practice sessions. A total of 176 HAEs were recorded across 127 tackle events involving an instrumented athlete participating as the ball carrier (n = 70 tackle events), tackler (n = 82 tackle events); in 24 tackle events both the ball carrier and the tackler were instrumented. The overall mean peak resultant linear acceleration was 15.6 g, peak resultant rotational velocity was 10.7 rad/s, and peak resultant rotational acceleration was 1296 rad/s². Head contact occurred in 85 HAEs (48.3%).

The tackling form grading rubric step with the greatest number of sub-steps not performed was the Head Placement step indicating a tendency for athletes to lower their head during a tackle (n = 61 tackles (48.0%) where at least one sub-step was missed). Tackles where a Head-Placement sub-step was missed resulted in greater head kinematics overall than those with where all Head-Placement Sub-Steps were completed.


Conclusions: Preliminary results of this study indicate that tackles where head contact occurred resulted in greater head kinematics than tackles where no head contact occurred. Future work will seek to further evaluate the relationship between tackling form grades and sub-steps that are associated with increased head kinematics. Final results will identify potential deficiencies in tackling form which can inform future interventions designed to improve athlete safety.




Acknowledgements (Optional): : Acknowledgements: We thank the youth football organization for participating, and Tina Strates for assisting with this study. NIH NICHD (K25HD101686) and Wake Forest University School of Medicine Dean’s Award funded this study.


References (Optional): : References: [1] Powell JW et al., J Am Med Assoc., 282(10), 1999. [2] Macy JT et al., Pub He Rep., 136(5), 2021 [3] Maerlender A et al., Ann Biomed Eng., 48(11), 2020 [4] Youth Football Online [5] Marks ME et al., Ann Biomed Eng, 50(11), 2022