Immediate effect of different forefoot wedges on standing stability in young adults

Abstract

The aim of this study was to investigate the immediate effect of wearing the functional insoles with different slopes of forefoot wedges on postural stability in young adults during quiet stance. In this study, the functional insole was composed of a forefoot wedge and a medial arch support. Twelve healthy young adults (six males and six females) participated. Each subject wore sneakers with and without functional insole and stood as still as possible on a force plate with feet together, arms by side and head facing ahead for 60 s, while eyes open and eyes closed, respectively. The functional insole was applied in the random sequence of no insole, wearing insole with a medial arch and a four-degree forefoot wedge, as well as wearing insole with a medial arch and an eight-degree forefoot wedge. The sway areas as well as the maximal excursions of the center of pressure (COP) in anterior-posterior (AP) and medial-lateral (ML) directions were used to evaluate the static postural stability. During stance with feet together and eyes closed, the sway area and maximal excursion of the COP in the AP direction were significantly decreased when wearing an eight-degree forefoot wedge functional insole. Since the reduced displacements of the COP indicated better postural control, it was suggested that the functional insole with an eight-degree forefoot wedge and a medial arch support might be beneficial to improve the postural stability in patients with impaired balance control, especially for whom having high risk of forward falls.