Effects of an Instability Training Program Using Global Versus Selective Instability Devices

The goal of this clinical trial was to compare the effects of a 4-week balance training programme using a GID or SID on functional dynamic balance and functional ankle stability in young healthy amateur soccer players. The main question it aimed to answer are: 1\. Are there differences between using GID or SID in improving dynamic balance according to the Modified Star Excursion Balance Test (mSEBT) and the Emery test, and in improving functional ankle stability according to the Side Hop Test? Participants were randomly allocated into two groups: GID balance training (i.e., with a BOSU®) and SID balance training (i.e., with Blackboard). The randomization and allocation were performed using the sealed envelope method. Both groups performed on a 4-weeks balance training program with the assigned device. Participants were asked to: * Perform a 5-minute conventional warm-up (cycling and active anke mobility exercises) * Perform four balance exercises with a 3-kg medicine ball, on the unstable surface device assigned to each group (explanation of the exercises in the detailed description) Researchers compared the results of the GID group with those of the SID group to determine the differences between devices in the improvement of dynamic balance and functional stability of the foot and ankle.