Immediate effects of silicone insoles on gait pattern in patients with flexible flatfoot

Background: Flatfoot in which a normal arch fails to develop is a common deformity in both children and adults. A frequently-used treatment is an over-the-counter insole to normalize foot mechanics and relieve pain. This study was designed to evaluate the effects of over-the-counter silicone insoles on the gait patterns of patients with flexible flatfoot. Methods: Thirty-four adults (24 women and nine men, average age 43.7 +/- 9.7 years) with bilateral symptomatic flatfoot deformities were included in the study. Flatfoot was diagnosed by a lateral talometatarsal angle of more than 4 degrees and a talocalcaneal angle of more than 30 degrees. Three-dimensional gait analysis and video recordings were done at a single session. All patients walked at self-selected speeds over a 10-meter walkway with and without insoles. Time-distance parameters and kinematic and kinetic characteristics of gait in the sagittal plane were evaluated by a quantitative gait analysis system. Results: Mean lateral talometatarsal and talocalcaneal angles were 6.3 +/- 2.5 degrees and 56.1 +/- 8.6 degrees, respectively. There was no difference in gait parameters with or without the insoles. Conclusions: Over-the-counter insoles have no beneficial effect in normalizing forces acting on the foot and on the entire lower extremity in adults with flexible flatfoot.