Countermovement Jump as Tool to Predict Injuries in High-Performance Youth Volleyball and Basketball Players: A One-Season Observational Prospective Study.

OBJECTIVE

To evaluate the association of the weekly countermovement jump (CMJ) performance with injuries during an entire season of high-performance youth volleyball and basketball players.

DESIGN

An observational prospective study.

SETTING

Private practice within a high-performance sports center.

PARTICIPANTS

Forty-nine youth high-performance volleyball and basketball players were enrolled (female volleyball, n = 12; female basketball, n = 17; male basketball, n = 20).

ASSESSMENT OF RISK FACTOR: All players were monitored weekly during an entire season by performing a maximal CMJ test 48 hours after every competition. All the sports injuries per 1000 Ae (athlete exposure) were registered.

MAIN OUTCOME MEASURES: Authors hypothesized that lower CMJ performance would be associated with a higher incidence of injuries during the season.

RESULTS

The rate of injuries was 1.61 per 1000 Ae, with ankle (63.33%) being the most frequently affected region. Female basketball players showed a higher injury rate than the rest of the players (2.54 per 1000 Ae, P = 0.045). Binary logistic regression analysis demonstrated that week-to-week reductions in CMJ performance predicted lower limb injuries ( P < 0.001, 95% CI = 0.86-0.95, Nagelkerke R 2 = 11.4%). When considering CMJ during preseason, it did not show any significant association with injuries sustained during the rest of season ( P > 0.05).

CONCLUSIONS

Reductions in weekly CMJ performance (>8.2%) can help predict lower limb injuries in youth volleyball and basketball players. An isolated CMJ performance evaluation during preseason is not enough to predict injuries during the sports season.