Effects of the Custom Mold with a Raised Ridge around the Perimeter Foot Orthoses on Dynamic Postural Control in Chronic Ankle Instability

Background and Objectives: Among the foot orthoses prescribed to improve postural control in chronic ankle instability, foot orthoses designed to affect both types of mechanical and functional instability have a limited research background. In the present study, a type of foot orthosis named the custom mold with a raised ridge around the perimeter was designed, and manufactured, and its effect on the dynamic posture control of the subjects was investigated. Methods: This study was a quasi-experimental type in which 30 active young people with chronic ankle instability were selected from sports clubs and divided into two groups. One of these groups used custom mold foot orthoses (CFO) and the other group used custom mold with a raised ridge around the perimeter foot orthoses (CRFO). Dynamic postural control of the participants was evaluated before and after one month with the star excursion balance test (SEBT). A repeated measured statistical test was used to evaluate the obtained data. Results: Both types of foot orthoses increased the reaching distance of the star excursion balance test (SEBT), but the CRFO was significant in this field, so that after one month in medial (P = 0.045), posteromedial (P = 0.002), and anteromedial (P ˂ 0.001) directions, significant differences were observed between the two groups. Conclusion:  The CRFO can put the subtalar joint in optimal conditions and change the amount of input resulting from the stimulation of the mechanoreceptors in the plantar area of the foot, thus increasing the improvement of dynamic postural control; however, more studies are needed to prove this claim.