Effectiveness of warm-up and dynamic balance training in preventing anterior cruciate ligament injuries in college gymnasts: a 3-year prospective study for one team.

Abstract

The effect of trunk stability and dynamic balance warm-up exercises on physical functional improvement remains unelucidated. This study examined whether exercises could prevent anterior cruciate ligament (ACL) injury and improve trunk muscle activation and dynamic balance in gymnasts. This comparison study, involving gymnastics practice sessions, included 31 university gymnasts and was conducted in two periods: 1 year of observation followed by 2 years of intervention. Participants performed a trunk and dynamic balance warm-up exercise program during the intervention. The effect of exercise on the incidence of ACL injury was evaluated. In addition, the paired t-test was used to compare the Y-balance distance and the changes in muscle thickness associated with trunk muscle activation at rest and during plank. ACL injury risk during the intervention was significantly lower, with a relative risk of 0.23 (P=0.02, 95% CI: 0.06-0.88). Changes in muscle thickness with activation of the transversus abdominis (P<0.01, mean difference 4.1, 95% CI: 9.97-28.07, Cohen's d=0.52), internal oblique (P<0.01, mean difference 5.2, 95% CI: 9.72-21.55, Cohen's d=0.65), and external oblique (P<0.01, mean difference 5.5, 95% CI: 20.44-39.09, Cohen's d=0.71) muscles were significantly higher during the intervention. The Y-balance distance was also significantly greater in the posterior medial reach (P<0.01, mean difference 3.3, 95% CI: 1.56-6.26, Cohen's d=0.46) during the intervention. Exercise-based warm-up programs may decrease ACL injuries. It can improve physical functions, such as the rate of change in trunk muscle thickness and the posterior medial distance during Y balance.