comparing the effects of simultaneous eight-week stretching / strengthening trainings with core stability exercises on the flat foot deformity of 9- to13- year -old female students

background: this study aimed to compare the effects of simultaneous eight-week stretching and strengthening trainings and exercises with core stability exercises on the flat foot deformity of female students with the age ranges from 9 to 13 years.   methods and materials: in the present quasi-experimental study on 130 female students, 60 girls with flat feet and the age ranges from 9 to 13,were selected randomly and divided into two experimental groups (n = 20 in each group) and one control group (n = 20). the samples were selected using navi loss, and then staheliarch index was evaluated. the experimental groups received the treatment(one group received stretching and strengthening exercises and the other group received core stability exercises for 45 minutes, three times a week) for 8 weeks, but the control group received no treatment and was engaged in daily routine activities. the data were analyzed through analysis of independent samples t-test at the significance level of p≤.05. results: post-test of arch corrective exercises revealed a significant difference among the three groups so that the subjects of both the experimental groups, compared to the control group, had a significant decrease in the angle of the back nut side while the difference between the two experimental groups was not statistically significant (p< .001). also, in the second experimental group, exercises influence on the arch more than that of the first experimental group (p