Comparison of stop-X and knee control training on side cut kinetics in futsal players with dynamic knee valgus: a...

Non-contact anterior cruciate ligament (ACL) injuries are a significant challenge for young athletes in soccer and futsal. Dynamic knee valgus and ground reaction force are modifiable risk factors for non-contact injuries in the side cut movement that is frequently performed by athletes. The goal of this study was to contrast the effects of Stop-X and knee control protocols on kinetic variables of the side cut of futsal players with dynamic knee valgus. Forty-five male futsal athletes with dynamic knee valgus were randomly assigned to two training groups, including Stop-X (n = 15) and knee control (n = 15) groups, and a control group (n = 15). Dynamic knee valgus was recorded by placing a camera at a certain distance (230 cm) from the force plate and calculated with Kinovea software. A force plate was used to evaluate the ground reaction force (sampling rate: 1000 Hz). A significant decrease in dynamic knee valgus was observed in the training groups (P = 0.001, η²p = 0.760). Also, an increase in vertical ground reaction force (P = 0.001, η²p = 0.691) and medial-lateral force (P = 0.038, η²p = 0.132), along with a significant decrease in COP_x (P = 0.007, η²p = 0.227), were observed in the training groups. Both Stop-X and knee control training may similarly contribute to better knee alignment in high-risk athletes. However, further research is needed to better establish this issue. These exercises, incorporated into routine training movements (such as lateral cuts), reduce dynamic knee valgus and improve ACL injury risk factors. Clinical trial registration: This study adhered to CONSORT guidelines for randomized controlled trials and had been registered in the Iranian Registry of Clinical Trials (IRCT20241230064223N1, Date:2025-01-18).