Use of postural insoles to correct dynamic knee valgus in youth soccer players: a randomized, controlled, double-blind clinical trial

Abstract

Introduction: Altered alignment of the lower limb promotes dynamic knee valgus (DKV), the foot pronacion is among the injuries associated with DKV and is less studied, as well as their treatment through postural insoles which generate elevation of the medial longitudinal plantar arch of the foot. Objective: To analyze the effect of using a postural insole in correcting DKV in young soccer players. Materials and Method: The following parameters were analyzed: the frontal plane projection angle (FPPA) of the knee by video capture during the lateral step down and the center of pressure excursion index (CPEI) by Computerized Baropodometric Analysis. The sample was randomly divided into 2 groups: Corrective Postural Insole Group (CPIg) and Placebo Postural Insole Group (PPIg). Results: The repeated measures Anova showed significant differences with an increase between the means obtained in the FPPA (P=0.002) and CPEI (P=0.034) assessments of the PPIg group. The means of the evaluations in the CPIg were significant, with an increase for the FPPA (P=0.003), and not significant for the CPEI (P=0.793), but the Bonferroni adjustment showed a significant increase in the means of the FPPA between Ev1 x Ev3 (difference: 6.22º; P=0.001) in PPIg; and between Ev1 x Ev3 (difference: 6.86º; P=0.016) and Ev2 x Ev3 (difference: 4.14º; P=0.015) in the CPIg. Conclusion: The findings allow us to conclude that the use of postural insoles with 5º corrective shims was not effective in reducing DKV, since the PPIg (which did not use corrective shims) also showed the same increase in FPPA.