Comparative Analysis of Center of Pressure Responses During Defensive Landing in Professional and Novice Volleyball Players

Objective This study aimed to evaluate the center of pressure (CoP) movements during landing after a block in professional volleyball players and to compare them with novice players.Methods In this cross-sectional descriptive study, ten professional and ten novice male volleyball players (with a minimum of two years of regular training) participated.CoP movements were assessed during five blocking conditions: static jump, step-side block to the right and left, and long cross-step block to the right and left.CoP displacement variables-including speed, range of sway, and RMS-were recorded during landing using a 3D motion capture system and force plates.Measurements were analyzed separately in the anterior-posterior (AP) and mediallateral (ML) directions. ResultsThe findings indicated that novice players generally exhibited greater CoP sway and higher RMS values during landing compared to professionals.Specifically, CoP sway in the ML direction was significantly greater in novices during static and left short-step blocks.Additionally, RMS values were significantly higher in most tasks among novices.However, there was no significant difference between groups in CoP speed. ConclusionThe results suggest that novice players demonstrated greater variability (RMS) in CoP movements, even though they showed less overall sway amplitude.This pattern-higher variability with reduced sway-may reflect a "freezing" of degrees of freedom, a strategy commonly used by less experienced individuals to preserve balance.Such a strategy may compromise dynamic stability and increase the risk of injury.