Reliability and validity of current physical examination techniques of the foot and ankle

Background: This literature review was undertaken to evaluate the reliability and validity of the orthopedic, neurologic, and vascular examination of the foot and ankle. Methods: We searched PubMed - the US National Library of Medicine's database of biomedical citations - and abstracts for relevant publications from 1966 to 2006. We also searched the bibliographies of the retrieved articles. We identified 35 articles to review. For discussion purposes, we used reliability interpretation guidelines proposed by others. For the κ statistic that calculates reliability for dichotomous (eg, yes or no) measures, reliability was defined as moderate (0.4-0.6), substantial (0.6-0.8), and outstanding (> 0.8). For the intraclass correlation coefficient that calculates reliability for continuous (eg, degrees of motion) measures, reliability was defined as good (> 0.75), moderate (0.5-0.75), and poor (< 0.5). Results: Intraclass correlations, based on the various examinations performed, varied widely. The range was from 0.08 to 0.98, depending on the examination performed. Concurrent and predictive validity ranged from poor to good. Conclusions: Although hundreds of articles exist describing various methods of lower-extremity assessment, few rigorously assess the measurement properties. This information can be used both by the discerning clinician in the art of clinical examination and by the scientist in the measurement properties of reproducibility and validity.