# Targeted literature search and evidence map

Search conducted **26 October 2026**. This is a targeted narrative search to contextualize descriptive injury burden, not a systematic review, meta-analysis or clinical guideline. Twelve publications were selected, spanning 2006–2025. The search date does not imply that every publication before that date was assessed.

## Questions and sources

The questions concerned surveillance definitions; exposure and availability denominators; frequency versus consequences; hamstring and muscle injury context; public/media recording validity; return endpoints; and calendar interpretation.

Discovery used the connected **Consensus** scientific-search service and web searches directed to PubMed, original journal publishers and legitimate open full text. Consensus records were fetched before use. Titles, author lists, publication years, journals, DOI identifiers and the specific claims were verified against PubMed and/or the original publication record. Some journal pages returned access errors; accessible abstracts, publisher records and legitimate open full text were used instead. Access controls were not bypassed.

Representative queries:

- `football injury surveillance consensus definitions injury burden player availability team performance injury audit public media Transfermarkt validity`
- `Fuller 2006 consensus injury definitions data collection procedures football`
- `IOC 2020 consensus statement injury illness surveillance bjsports-2019-101969`
- `Football-specific extension Markus Waldén 106405`
- `Why we should focus on the burden of injuries and illnesses`
- `Hagglund injuries negatively affect team performance professional football 11 year UEFA 2013`
- `Hamstring injury rates have increased during recent seasons`
- `Epidemiology of muscle injuries in professional football`
- `Transfermarkt injury data validity reliability professional football media-based injury surveillance validation study`
- `Injury Analysis in Professional Soccer by Means of Media Reports`
- `Analysis of more than 20000 injuries European professional football citizen science`
- `2016 Consensus statement on return to sport`
- `No major changes in injury incidence 2022/23 UEFA 2025`

## Selection and appraisal limits

Selection favored directly relevant professional-football cohorts, direct validation studies and foundational consensus or methodological publications. Unverified project/blog claims, synthetic-data injury-prediction projects and unrelated estimates were excluded from the scientific discussion. No preregistration, independent dual screening, formal risk-of-bias assessment, exhaustive citation chasing or quantitative pooling was performed. Discovery counts are not presented as a PRISMA flow. No claim of comprehensive coverage or evidence certainty rating is made.

The reference registry identifies each source's evidence type, intended claim and limitation. Four consensus statements support definitions or interpretation [1–3,10]; one editorial supplies conceptual burden framing [4]; four prospective cohorts or subanalyses provide football context [5,6,11,12]; two studies evaluate public-record validity or comparability [7,8]; one prospective structured media-surveillance study informs collection design [9]. Source numbers correspond to `references/references.json`.

Consensus recommendations are not empirical validation of the Kaggle file. Clinical cohorts and media archives are not interchangeable. Several UEFA publications share a research program and may overlap in participants, so they are not independent replications to be pooled or counted as separate confirmations. The Kaggle source's upstream clinical verification remains unconfirmed.

## Reuse and citation

Discussion claims are paraphrased and linked directly to DOI pages. No publisher figure, table, photograph, full abstract or long quotation is reproduced. The website uses charts generated from the separately attributed project dataset. Bibliographic citation does not transfer article copyright or imply endorsement. Machine-readable metadata and portable citations are provided in `references/references.json` and `references/references.bib`.

Full references, evidence type, relevance and primary verification links are in the registry. The English and Spanish discussions share stable citation numbers and DOI links.