Orthotic devices like insoles are widely used to prevent or correct deformities and improve performance. The aim of present study was to investigate immediate effects of using insoles with various wedges on center of pressure (COP) indices and comfort rating during load lifting. Thirty able-bodied males participated in this quasiexperimental study. Repeated measures analysis of variance test with a Bonferroni correction (P < 0.0014) was used to compare dependent variables among nine insole wedge conditions. The results showed these significant differences: anterior-lateral wedge with anterior and medial wedges for standard deviation of COPx values; anterior-lateral wedge with non-wedge, posterior, lateral and posterior-medial wedges for standard deviation of COPy velocity values; anterior-lateral wedge with anterior and posterior-medial wedges for total mean velocity of COP values (P ¼ 0.001). Also, the anterior-lateral wedge tended to increase in other COP indices and decrease in comfort rating compared to other wedges. Also, a significant negative relation between comfort rating and almost all COP indices was observed during load lifting (P < 0.05). These findings show that using anterior-lateral wedge for insole creates less stability and comfortability which may introduce as a non-optimal condition for insole designation. These results can be useful for designation of shoe or insole for work environments
