Effects of Orthotic Correction of Hallux Valgus on Three-Dimensional Moments of Ankle Joint during Gait in Individuals with Hallux Valgus Deformity

Background Although many different types of foot-toe orthoses have known to correct hallux valgus deformity, most previous studies focused on the effects of a foot-toe orthosis as a clinical intervention for hallux valgus (HV) on simple gait function or alignment of the foot and ankle joints. Purpose To investigate effects of a hard and soft type foot orthoses on three-dimensional (3D) kinetic moments of ankle joints known to contribute to ankle arthrosis in individuals with HV using a force platform system based on motion analysis during gait. Study design This was a repeated-measures design. Methods Kinetic 3D moment data were obtained from 26 participants with HV. Two force platforms were used to collect kinetic data in three different foot-toe orthosis conditions during free walking. Repeated-measures analysis of variance was used to determine the effect of each foot-toe orthosis condition on ankle moment variables. Results There were significant differences in the maximal plantar flexion moment, second peak eversion moment, and maximal external rotation moment occurred at the terminal stance phase of the ankle joints between without foot orthosis and hard foot orthosis conditions ( p <0.05). In addition, there were significant differences in maximal plantar flexion moment occurred at the late stance phase during gait between without foot orthosis and soft foot orthosis conditions ( p < 0.05). Conclusions The results indicated the potential relationship between HV deformity and ankle osteoarthrosis through increasing ankle moments at the terminal stance under the without foot-toe orthosis condition. Particularly, the application of a hard foot-toe orthosis could contribute to treatment and prevention of ankle osteoarthrosis as well as HV correction.