An Investigation of Factors Associated With Head Impact Exposure in Professional Male and Female Australian Football Players

Jonathan Reyes, Biswadev Mitra, Andrew McIntosh, Patrick Clifton, Michael Makdissi, Jack V.K. Nguyen, Peter Harcourt, Teresa S. Howard, Peter A. Cameron, Jeffrey V. Rosenfeld, Catherine Willmott

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background: Exposure to head acceleration events (HAEs) has been associated with player sex, player position, and player experience in North American football, ice hockey, and lacrosse. Little is known of these factors in professional Australian football. Video analysis allows HAE verification and characterization of important determinants of injury. Purpose: To characterize verified HAEs in the nonhelmeted contact sport of professional Australian football and investigate the association of sex, player position, and player experience with HAE frequency and magnitude. Study Design: Descriptive epidemiology study. Methods: Professional Australian football players wore a nonhelmeted accelerometer for 1 match, with data collected across 14 matches. HAEs with peak linear accelerations (PLAs) ≥30g were verified with match video. Verified HAEs were summarized by frequency and median PLA and compared between the sexes, player position, and player experience. Characterization of match-related situations of verified HAEs was conducted, and the head impact rate per skill execution was calculated. Results: 92 male and 118 female players were recruited during the 2017 season. Male players sustained more HAEs (median, 1; IQR, 0-2) than female players (median, 0; IQR, 0-1; P =.007) during a match. The maximum PLAs incurred during a match were significantly higher in male players (median, 61.8g; IQR, 40.5-87.1) compared with female players (median, 44.5g; IQR, 33.6-74.8; P =.032). Neither player position nor experience was associated with HAE frequency. Of all verified HAEs, 52% (n = 110) occurred when neither team had possession of the football, and 46% (n = 98) were caused by contact from another player attempting to gain possession of the football. A subset of HAEs (n = 12; 5.7%) resulted in players seeking medical aid and/or being removed from the match (median PLA, 58.8g; IQR, 34.0-89.0), with 2 (male) players diagnosed with concussion after direct head impacts and associated PLAs of 62g and 75g, respectively. In the setting of catching (marking) the football, female players exhibited twice the head impact rate (16 per 100 marking contests) than male players (8 per 100 marking contests). Conclusion: Playing situations in which players have limited control of the football are a common cause of impacts. Male players sustained a greater exposure to HAEs compared with female players. Female players, however, sustained higher exposure to HAEs than male players during certain skill executions, possibly reflecting differences in skill development. These findings can therefore inform match and skill development in the emerging professional women’s competition of Australian football.

Original languageEnglish
Pages (from-to)1485-1495
Number of pages11
JournalAmerican Journal of Sports Medicine
Volume48
Issue number6
DOIs
Publication statusPublished - 1 May 2020

Keywords

  • head impact biomechanics
  • nonhelmeted accelerometer
  • professional athletes
  • sports injury
  • sports-related concussion
  • wearable accelerometers

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