RESUMO
BACKGROUND: Besides arch-supportive insoles, sensorimotor insoles are used for the treatment of flatfoot in children. The aim of this study was to compare the effect of both types of insoles on the arch-supporting muscles and clinical aspects in children with flexible flatfoot. MATERIAL AND METHODS: 52 children with flexible flatfoot (mean age of 8.22.7 years) were enrolled. Supportive, sensorimotor, and placebo insoles were compared. Muscle activity was detected by surface electromyography during the midstance phase. Valgus index, foot and ankle disability index (FADI) and pain were assessed at enrolment and after 6 and 12 months. Mixed-design ANOVA was used for statistical evaluation. RESULTS: Supportive and sensorimotor insoles caused significantly lower activity in the tibialis anterior in comparison to placebo insoles regarding the parameter Mean. No significant differences could be detected between both types of therapeutic insoles. Supportive insoles showed a significant decrease regarding the parameter Amplitude of the peroneus longus. Placebo insoles produced an increase in the valgus index, while both therapeutic insoles did not induce any changes. The sensorimotor insoles induced an increase in FADI, while the supportive and placebo insoles had no significant effect on this parameter. CONCLUSIONS: 1. Supportive and sensorimotor insoles potentially influence muscle activity in the lower leg. 2. Both could influence the longitudinal arch in flat feet. 3. While placebo insoles caused a deterioration of the valgus index, both kinds of therapeutic insoles could possibly prevent the progression of the flatfoot. 4. Clinical studies including more clinical aspects and long-term observations are necessary.