A Simple Field Tapping Test for Evaluating Frequency Qualities of the Lower Limb Neuromuscular System in Soccer Players: A Validity and Reliability Study

Abstract

Over the years, the foot tapping test protocol has been proposed by scientists to identify the capabilities of the lower limb neuromuscular system in the medical context; however, to our knowledge, no studies have established its usefulness and relationship to athletic performance. The aim of the present study was to test the reliability, criterion validity and sensitivity of a new foot tapping (TAP) test, and to examine its relationship with proxies of athletic performance in soccer players. Forty voluntary soccer players of two different levels participated in this study (20 players from the national level: age: 22.6 ± 2.5 years and 20 players from regional level: 25.1 ± 3.6 years). They performed the TAP test on two separate occasions to test its relative and absolute reliability. To examine the criterion validity of the TAP test, all participants performed four types of jumps, sprint tests, agility tests, the Wingate test and the finger tapping test considered a gold standard tapping test. The sensitivity was assessed with national and regional player levels. The TAP test presented a high relative and absolute reliability with intra-class correlation coefficient ICC > 0.90, standard errors of measurement SEM < 5% and mean difference ±95% limits of agreement equal to 0.2 ± 0.8 tap·s−1. National level players showed a higher TAP score (p < 0.001; dz = 1.96, large) compared to regional players (9.68 ± 1.41 tap·s−1 vs. 7.28 ± 1.01 tap·s−1, respectively) and the value of area under curve measured by the receiver operating characteristic curve technique was 0.95 (95% CI: 0.827–0.990). The TAP test showed a significant association with the finger tapping test (r = 0.84, p < 0.001), whereas no correlation was seen between the TAP test and all the other physical tests measured. The TAP test could be considered a valid and reliable test to assess lower limb neuromuscular ability in soccer players.