Hamstring Tightness and Its Association with Low Back Pain in College-Level Kabaddi Players: A Cross-Sectional Study

Abstract

Background: Kabaddi demands intense biomechanical load on the lower back and posterior chain. Players frequently execute explosive sprints, drop into low defensive stances, twist violently to escape tackles, and absorb high-impact forces. Shortened or inflexible hamstring musculature is hypothesized to increase posterior pelvic tilt, flattening lumbar lordosis and transferring mechanical stress to the lumbar spine. However, objective empirical data evaluating this relationship in competitive kabaddi athletes remain limited.
Objective: To determine the prevalence of hamstring tightness among college-level kabaddi players and to analyze its cross-sectional association with low back pain (LBP).
Methods: In this cross-sectional study, 428 college kabaddi players aged 18–25 years were recruited across university training programs. Hamstring length was evaluated bilaterally using the Active Knee Extension (AKE) test, with an extension deficit exceeding 20° defining hamstring tightness. LBP presence (past 12 months and current), pain intensity, and functional disability were assessed using the Standardized Nordic Questionnaire, the Numeric Rating Scale (NRS), and the Oswestry Disability Index (ODI), respectively. Prevalence rates were calculated with 95% Wilson confidence intervals (CIs). Group comparisons were evaluated using Chi-square tests, Student’s t-tests, and Mann–Whitney U tests. Associations were modeled using binary logistic regression adjusting for age, BMI, and playing experience.
Results: Hamstring tightness was identified in 321 of 428 players (75.00%; 95% CI: 70.67%–78.86%), while 329 players reported LBP within the previous 12 months (76.87%; 95% CI: 72.63%–80.62%). The prevalence of LBP among players with hamstring tightness was 75.39% (242/321) compared to 81.31% (87/107) in those with normal hamstring length. Univariable analysis demonstrated an odds ratio (OR) of 0.70 (95% CI: 0.40–1.22; p = 0.206) for LBP in players with hamstring tightness. Mean AKE deficits did not significantly differ between players with LBP (19.30° ± 3.53°) and those without (19.76° ± 3.29°; p = 0.244). AKE deficit showed negligible correlation with pain intensity (ρ = -0.047, p = 0.334) and ODI disability scores (ρ = -0.047, p = 0.335). Multivariable logistic regression confirmed that hamstring tightness was not independently associated with 12-month LBP (adjusted OR = 0.70, 95% CI: 0.40–1.22; p = 0.206).
Conclusion: Both hamstring tightness and low back pain are highly prevalent among college-level kabaddi players. However, hamstring tightness alone was not significantly associated with back pain presence, intensity, or functional disability. Multi-factorial prevention strategies incorporating core endurance, load management, and trunk biomechanics are recommended over isolated flexibility training.