725 MEP091 – Its time to slash injuries: video analysis of in-game physical contacts and suspected-injuries in Canadian youth box lacrosse
Bibliographic record
Abstract
Background Lacrosse (Canada’s National summer-sport) hosts >80,000 registrants annually. Unfortunately, few prevention efforts have been examined in Box lacrosse. Therefore, examining in-game player-to-play physical-contacts is paramount for future prevention work. Objective To examine the incidence rates (IRs) of physical-contacts, including bodychecks (BC; high-intensity trunk-contact), high-intensity cross-checks (HICC; two-handed push with stick), head contacts (HCs), and video suspected-injuries (SI) across elite division-A youth (ages 9–16) Box lacrosse tournament-play. Design Cross-sectional video-analysis study. Setting Canada. Participants Elite Division-A (highest division) Box lacrosse players within U11 (ages 9–10), U13 (ages 11–12), U15 (ages 13–14), and U17 (ages 15–16) levels. Assessment of Risk Factors Comparison of physical-contact measures during tournament-play between the 4 age levels (n=24 games/6 per level). Main Outcome Measurements Games were analyzed using Dartfish video-analysis software and validated physical-contact criteria. Poisson regression analyses (adjusted for cluster by game and offset by playing time) were used to compare the IRs (per 100 game-minutes) using incidence rate ratios (IRR) for BCs, HCs, HICCs, and video-SIs. Results When compared with U13 (reference), the BC IR was 4.34-fold higher in U11 (IRR=4.34;95%CI:1.74–10.81), 3.26-fold higher in U15 (IRR=3.26;95%CI:1.31–8.13), and 3.65-fold higher in U17 (IRR=3.65;95%CI:1.48–9.00). Moreover, the HICC IR was 38% higher in U11 (IRR=1.38;95%CI:1.00–1.90), did not differ for U15, and was 47% lower in U17 (IRR=0.53;95%CI:0.35–0.78). The HC IRs were 3.81-fold higher in U11 (IRR=3.81;95%CI:2.38–6.11) and 3.40-fold higher in U17 (IRR=3.40;95%CI:2.21–5.23), but not different in U15 (when compared with U13). SI-IRs in U11 (IR-U11=6.24;95%CI:3.54–10.98) were 3.91-fold higher than in U13 (IR-U13=1.60;95%CI:0.60–4.25) (IRR=3.91; 95%CI:1.26–12.12) and did not differ for U15 nor U17. Conclusion The high BC, HICC, and HC IRs in U11 are concerning and likely associated with the 3-fold higher SI-IR. Lacrosse Canada should consider exploring strategies related to policy that lowers BC, HICC, and HC physical-contacts in U11 to promote player safety.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".