Preventive Effect of Cross-motion Swing Exercise on Groin Pain in High School Male Soccer Players: A Cluster Randomized Controlled Trial.

Background: Groin pain in soccer players arises from various causes, most commonly kicking, and as such can significantly affect performance. A new form of exercise, the cross-motion swing exercise (CMS), may help prevent groin pain but is untested.

Purpose: To evaluate the effectiveness of the CMS in preventing groin pain in high school soccer players.

Study design: Randomized controlled trial; Level of evidence, 1.

Methods: This study involved 135 male high school soccer players <18 years from 4 teams competing in a high school soccer league in Japan. Teams were randomly assigned to an intervention group (2 teams; n = 65 players) or a control group (2 teams; n = 70 players). The intervention group performed the CMS in addition to their usual warm-up, emphasizing coordination and kicking movements, while the control group continued their usual warm-up exercise. The intervention period lasted 16 weeks, with compliance monitored weekly. Data were collected through weekly Google form surveys. The primary outcome was the incidence of groin pain at any time during the study period.

Results: The intervention group had a significantly lower incidence of groin pain (9.4%) compared with the control group (23.1%). Cox proportional hazards regression analysis indicated a significantly reduced risk of groin pain in the intervention group (hazard ratio, 0.309; 95% CI, 0.108-0.880; P = .028). The number of injuries was 6 in the intervention group and 18 in the control group, and injuries due to the kicking motion were 0 in the intervention group (0%) and 7 in the control group (38.9%).

Conclusion: The CMS significantly reduced the incidence of groin pain in high school soccer players. This suggests that coordination-based exercise, closely mimicking the appropriate sports-specific movement, was effective in reducing injury. The study supports incorporating the CMS into regular training to reduce the incidence of groin pain in male high school soccer players.

Trial registry and the registration number: This study has been registered as a clinical trial with the Universal Medical Information Network (UMIN) under the registration number UMIN000051311.