Exploratory associations between isometric strength, vertical jump performance, and psychomotor outcomes in elite traditional karate Kumite athletes

Background Traditional karate kumite requires the integration of physical, perceptual, and decision-making capacities. This exploratory study aimed to characterize selected neuromuscular and psychomotor variables and to examine their associations in elite traditional karate kumite athletes. Methods Twenty-seven adult male members of the Polish national traditional karate team participated in this observational, cross-sectional study. Isometric strength of the elbow and knee flexors and extensors was assessed using the BTE PrimusRS dynamometer. Vertical-jump performance was assessed using the squat jump (SJ), countermovement jump without arm swing (CMJ_noAS), and countermovement jump (CMJ) with the Optojump Next system. Psychomotor performance was assessed using the TEST2DRIVE battery, including simple reaction time, choice reaction time, hand–eye coordination, and spatial anticipation. Associations were examined using Pearson correlation coefficients. Because 70 pairwise correlations were analyzed, the Benjamini–Hochberg false discovery rate (FDR) procedure was applied to control for multiple comparisons. Results Several moderate associations were observed at the unadjusted level. The strongest association involving isometric strength was observed between right-arm extension strength and SPANT median motor time (r = 0.57; p = 0.002). Selected vertical-jump measures were also associated with psychomotor outcomes, including HECOR median motor time and CHORT response accuracy. However, none of the 70 correlations remained statistically significant after FDR correction (minimum adjusted q = 0.137). Conclusions The observed relationships between neuromuscular and psychomotor variables should be considered exploratory and hypothesis-generating. The present findings do not provide sufficient evidence to conclude that vertical-jump performance is more strongly associated with psychomotor performance than isometric strength. Further studies using larger samples, body-mass-adjusted strength measures, and karate-specific upper-limb and whole-body reaction tasks are required.