Explosive Arm Power, Hand Eye Coordination, and Volleyball Service Accuracy: Path Analysis

Background: Arm explosive power, hand eye coordination, and overhead-serve performance are related components of youth volleyball, but their cross-sectional associations require cautious interpretation. Objective: This study examined a prespecified pathway model linking arm explosive power and hand–eye coordination with two serve-test scores among junior high school extracurricular athletes. Method: Twenty students aged 13–15 years (9 boys and 11 girls) were purposively selected from 40 program members. Two regression submodels were estimated. Because all measures were collected in one fixed-order session and the two serve tests both used landing-zone scores, the analysis is descriptive and does not establish temporal or causal mediation. Results: Arm explosive power (β = .542, p = .004) and hand–eye coordination (β = .417, p = .019) were associated with the overhead-serve score. In the accuracy submodel, arm explosive power (β = .310, p = .019), hand–eye coordination (β = .334, p = .007), and the overhead-serve score (β = .476, p = .003) were associated with accuracy. Adjusted R² values were .557 and .856. Standardized indirect associations were .258 and .198. Sobel results were p = .016 and p = .038, respectively, but no bootstrap confidence intervals were available. Conclusion: The observed coefficients are consistent with the hypothesized pathway model in this selected sample, but small-sample instability, selection bias, unmeasured confounding, and operational overlap between the two serve tests limit inference and generalizability.