INTRODUCTION: Reliable and practical measures are necessary for making clinical decisions. The Navicular Drop Test (NDT) provides important information during evaluation of lower limbs. The purpose of the present article was to assess the psychometric properties of NDT as usually done in clinical environment, and to analyze a way to minimize the evaluator interference. MATERIALS AND METHODS: Fifteen people (30 feet), selected by convenience, participated. The NDT was performed independently by two investigators experienced in the test realization. The test was performed once in each foot, using a plastic caliper. Descriptive analysis of data was done. In order to evaluate the inter-examiner reliability, intraclass correlation index (ICC2,1) was used. The divergence between the measures was examined by the typical error measurement. RESULTS: The mean and standard deviation for the first and second examiner was 8.7 ± 5.3 and 9.7 ± 4.7 mm. The test showed excellent inter-examiner reliability (ICC = 0.93). The typical error of measurement was 2.16 mm. CONCLUSION: The procedures to minimize the interference of evaluator, paradoxically, showed worse indices of reliability. The NDT can be simplified by using common clinical tools and recorded from a single measure. Even though it showed a good reliability, the NDT contains a typical error of measurement which has to be considered for decision making. Changes in the test, sometimes required in a dynamic clinical environment, should be analyzed for maintenance of test properties.
Reproducibility of results; Physical examination; Foot
