{
  "abstract": "Objective To quantify concussion and head acceleration event (HAE) probability in rugby league tackles by tackle height and role and simulate seasonal counts across different tackle height distributions.Methods Using a prospective cohort study, data reflecting clinically diagnosed concussions (n=56) and HAEs (n=4632; measured via instrumented mouthguards from 23 081 tackles in 92 players) were collected during the 2023 men’s Super League season. Video analysis captured tackle heights for all concussive and accelerometer-measured tackles. Role-specific probabilities were calculated using cumulative link mixed models. Monte Carlo simulation quantified concussions and HAEs across the current tackle-height distribution and three lower tackle-height distributions (weighted redistribution (increased torso tackles), even redistribution (increased torso and lower body tackles) and observed law trial distribution).Results Ball-carriers experienced the highest concussion and HAE risk from head/neck contact compared with other tackle heights (eg, HAE ≥25 g; 2.7% vs 0.4%–1.1%), while tackler risk was similar. The number of ball-carrier concussions (16 vs 8–9) and HAEs (≥25 g; 830 vs 357–556) decreased with all lower tackle-height distributions. For tacklers, the only meaningful change was an increase in HAEs following the even redistribution of a lower tackle height (≥25 g; 2081 vs 2204). When considering both roles together, only even and weighted lower tackle-height redistributions reduced the total number of lower-to-moderate magnitude HAEs, with no meaningful differences observed for concussions or higher magnitude (≥55 g) HAEs.Conclusion Lowering the tackle height creates a protection paradox, benefiting ball-carriers, while potentially maintaining or increasing the risk for tacklers. Simulated findings may inform policy changes by estimating outcomes and allowing evaluation prior to implementation.",
  "authors": [
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "England Performance Unit, Rugby Football League, Manchester, UK"
      ],
      "name": "Cameron Owen"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK"
      ],
      "name": "James Tooby"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "Obesity Institute, Leeds Beckett University, Leeds, UK"
      ],
      "name": "Thomas Sawczuk"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK"
      ],
      "name": "Greg Roe"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "England Performance Unit, Rugby Football League, Manchester, UK"
      ],
      "name": "Gemma Phillips"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "England Performance Unit, Rugby Football League, Manchester, UK"
      ],
      "name": "Sean Scantlebury"
    },
    {
      "affiliations": [
        "England Performance Unit, Rugby Football League, Manchester, UK",
        "School of Biomedical Sciences, University of Leeds, Leeds, UK"
      ],
      "name": "Dane Vishnubala"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "Sydney School of Health Sciences, The University of Sydney, Camperdown, New South Wales, Australia"
      ],
      "name": "Andrew J Gardner"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "Division of Physiological Sciences and Health through Physical Activity, Lifestyle and Sport Research Centre, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa",
        "Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre, Stellenbosch, South Africa"
      ],
      "name": "Sharief Hendricks"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "School of Behavioural and Health Sciences, Australian Catholic University, Brisbane, Queensland, Australia",
        "Sports Performance, Recovery, Injury and New Technologies (SPRINT) Research Centre, Australian Catholic University, Brisbane, Queensland, Australia"
      ],
      "name": "Rich D Johnston"
    },
    {
      "affiliations": [
        "Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada"
      ],
      "name": "Ash T Kolstad"
    },
    {
      "affiliations": [
        "Centre for Health and Injury and Illness Prevention in Sport, University of Bath, Bath, UK",
        "Rugby Football Union, Twickenham, UK"
      ],
      "name": "Keith Stokes"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "World Rugby, Dublin, Ireland"
      ],
      "name": "Ross Tucker"
    },
    {
      "affiliations": [
        "Carnegie Applied Rugby Research (CARR) Centre, Leeds Beckett University, Leeds, UK",
        "England Performance Unit, Rugby Football League, Manchester, UK",
        "Division of Physiological Sciences and Health through Physical Activity, Lifestyle and Sport Research Centre, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa",
        "School of Behavioural and Health Sciences, Australian Catholic University, Brisbane, Queensland, Australia",
        "PREM Rugby, London, UK"
      ],
      "name": "Ben Jones"
    }
  ],
  "title": "Tackle higher or lower? Simulation to evaluate how changing the tackle height would impact the number of concussions and head acceleration events in men’s professional rugby league",
  "uid": "c857d70f-d5eb-5af4-b566-f698a226caa4"
}