Association Between Volleyball Participation and Knee Osteoarthritis in Community-Dwelling Adults: A Cross-Sectional Analysis of the Osteoarthritis Initiative

Objective: This cross-sectional study aimed to examine the association between recreational volleyball participation and knee osteoarthritis (KOA) risk in a community-based population, focusing on participation frequency, cumulative exposure periods, and clinical outcomes. Methods: Utilizing data from the Osteoarthritis Initiative (OAI) cohort (n = 2539; ages 45–79), volleyball engagement was assessed via the Historical Physical Activity Survey Instrument across four age periods (12–18, 19–34, 35–49, ≥50). Participants were stratified into non-volleyball, low-frequency, and high-frequency groups. Outcomes included knee pain (WOMAC score ≥ 1), radiographic OA (ROA), and symptomatic OA (SOA). Logistic regression models adjusted for age, sex, BMI, and race were employed to evaluate the associations. Results: Volleyball participation reported across all four age periods was associated with higher odds of ROA (adjusted OR = 2.394, 95%CI: 1.247–4.596, p = 0.009). High-frequency participation alone, however, was not associated with knee pain, ROA, or SOA (all p > 0.05). No significant associations were observed between cumulative participation and knee pain or SOA, and no dose–response relationship was found for participation frequency. Conclusions: Recreational volleyball participation was not associated with higher prevalence of knee pain or symptomatic radiographic KOA, outcomes that may be more clinically relevant than radiographic findings alone. Although participation across all four life periods was associated with higher odds of ROA, this structural finding should not be overinterpreted because it was based on a small subgroup and a non-monotonic pattern in a cross-sectional analysis.