INTERDAY RELIABILITY OF COUNTERMOVEMENT JUMP FORCE-TIME METRICS IN COMBAT FIGTHERS AND PHYSICALLY ACTIVE MEN
Countermovement jump, force-time curve, martial arts, reliability, performance testing.
Despite the height of the jump being the most analyzed variable, the force-time variables of the vertical jump with countermovement (SCM) describe aspects related to the movement strategy to perform the jump. The present study investigated the reliability of force-time metrics in different phases of the SCM in combat fighters and physically active individuals. Physically active men (n = 21) and combat fighters (n = 21) were tested on three different days, performing at least 4-7 SCM's at maximal effort each. All tests were performed using a force platform. Reliability was determined using the intraclass correlation coefficient (CCI) and the typical measurement error expressed as coefficient of variation (CVET). Metrics that obtained an effect size < 0.2, ICC ≥ 0.75 and CVET ≤ 10%, including the 95% confidence interval, were considered as “reliable.” The braking, propulsive and landing phases demonstrated reliable metrics. For the physically active group, the impulse of the landing phase was the only reliable variable, while the maximum and mean forces for the braking and propulsive phases and the impulse for the propulsive phase proved to be reliable variables for the combat fighters group. In addition, combat fighters demonstrated lower interday variation. In conclusion, our results suggest that the braking and propulsive phases have reliable force-time metrics for combat fighters and the landing phase for physically actives. Combat fighters and physically actives can obtain reliable metrics from one day of testing in different variables and phases. Finally, our results indicate that both groups can benefit from one or more days of testing.