Curve Characteristics of Biomechanical Variable Functions and Their Effect on Analyzing the Physical Dimensions of the Volleyball Blocking Skill

Abstract

Background: Volleyball blocking combines rapid positioning, vertical projection, and segmental coordination. Video-derived kinematic measures may help explain how these movement characteristics relate to technical execution.

Purpose: To describe selected block-jump kinematics and examine their exploratory associations with expert-rated technical performance in university volleyball players.

Methods: Ten members of the University of Al-Qadisiyah volleyball team each completed five successful blocking trials from court position 4 (50 trials in total). Two Galaxy S25 Ultra cameras recorded at 240 frames/s from lateral and posterior views. Kinovea 2025. was used to derive ascent velocity, peak hip height, and total movement time. Three evaluators rated five technique phases on a 100-point scale. The source analysis reported descriptive statistics and Pearson correlation coefficients between each kinematic variable and the technique score.

Results: Mean +/- SD values were 5.68 +/- 0.93 m/s for ascent velocity, 1.536 +/- 0.036 m for peak hip height, 2.69 +/- 0.48 s for movement time, and 71.16 +/- 4.72 points for technique. Reported correlations with the technique score were r = -0.78 for ascent velocity, r = 0.69 for peak hip height, and r = 0.91 for movement time.

Conclusion: The expert-rated technique score was strongly related to the measured movement characteristics. The directions - especially the negative velocity association and positive time association - should be interpreted as task- and scoring-specific rather than causal.