The effect of stop X exercises on balance, strength and range of motion of football players with dynamic knee valgus defect

Abstract Dynamic valgus of the lower limb is known as a risk factor associated with improper muscle function for many lower limb injuries, especially knee injuries. Therefore, the aim of the present study was to investigate the effect of Stop X exercises on the balance, strength and range of motion (ROM) of football players with dynamic knee valgus (DKV) defect. Thirty football players with dynamic knee valgus defect were selected purposefully and were randomly divided into two groups, control (n = 15) and training (n = 15). Stork tests, Y-balance test (YBT), goniometer, and digital dynamometer were used to evaluate static balance, dynamic balance, ROM, and hip abduction and external rotation strength, respectively. Analysis of covariance and dependent t-tests were used to compare the between and within group differences. There is a significant difference between the groups in the variables of hip abduction and external rotation strength and ROM, static balance and total score of YBT. The results demonstrated that performing Stop X exercises resulted in significant improvements strength and ROM of the hip, static and dynamic balance of football players with DKV defect, which show the importance of using these exercises to improve balance, muscle strength and ROM in this group of football players.