Validation and calibration of HeadCount, a self-report measure for quantifying heading exposure in soccer players

E. Catenaccio, J. Caccese, N. Wakschlag, Roman Fleysher, N. Kim, Mimi Kim, T. A. Buckley, W. F. Stewart, Richard B. Lipton, T. Kaminski, Michael L. Lipton

Research output: Contribution to journalArticle

10 Scopus citations


The long-term effects of repetitive head impacts due to heading are an area of increasing concern, and exposure must be accurately measured; however, the validity of self-report of cumulative soccer heading is not known. In order to validate HeadCount, a 2-week recall questionnaire, the number of player-reported headers was compared to the number of headers observed by trained raters for a men’s and a women’s collegiate soccer teams during an entire season of competitive play using Spearman’s correlations and intraclass correlation coefficients (ICCs), and calibrated using a generalized estimating equation. The average Spearman’s rho was 0.85 for men and 0.79 for women. The average ICC was 0.75 in men and 0.38 in women. The calibration analysis demonstrated that men tend to report heading accurately while women tend to overestimate. HeadCount is a valid instrument for tracking heading behaviour, but may have to be calibrated in women.

Original languageEnglish (US)
Pages (from-to)416-425
Number of pages10
JournalResearch in Sports Medicine
Issue number4
StatePublished - Oct 1 2016



  • head injuries
  • self-report
  • sex differences
  • Soccer

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

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