title: How useful are physical examination procedures? Understanding and applying likelihood ratios.
abstract: OBJECTIVE
  To describe the calculation and interpretation of likelihood ratios for examination procedures performed by certified athletic trainers.
  
  
  BACKGROUND
  Physical examination procedures or "special tests" are commonly taught to athletic training students and performed by certified athletic trainers. Likelihood ratios offer an approach to assessing test performance that incorporates estimates of sensitivity and specificity into a clinically useful value. We describe the calculation of likelihood ratios and the application of likelihood ratios to clinical decision making.
  
  
  CONCLUSIONS
  The performance characteristics of physical examination procedures taught and practiced in athletic training should be considered in the planning of course materials as well as test interpretation after a physical examination. Research is needed to better understand how well physical examination procedures, when performed by certified athletic trainers, identify those athletes with and without specific musculoskeletal injuries.
authors.affiliation: Department of Kinesiology, 276 Recreation Building, Pennsylvania State University, University Park, PA 16802, USA. crd4@psu.edu
authors.forename: Craig R
authors.initials: CR
authors.lastname: Denegar
authors.forename: Missy
authors.initials: M
authors.lastname: Fraser