Prevalence of Hamstring Tightness and Pelvic Asymmetry in Individuals With Chronic Low Back Pain

BackgroundChronic low back pain (CLBP) is a common musculoskeletal condition associated with pain, functional limitations, and altered lumbopelvic function.Hamstring tightness and pelvic asymmetry were clinically relevant physical characteristics that could occur in individuals with CLBP.However, limited evidence was available regarding their prevalence and association within the same CLBP population. ObjectiveThe study aimed to determine the prevalence of hamstring tightness (defined as a popliteal angle threshold of <130 degrees) and pelvic asymmetry (defined as a side-to-side difference of >1 degree) and to examine the association between these variables in individuals with CLBP. MethodsA cross-sectional observational study was conducted among 52 individuals with CLBP.After obtaining informed consent and screening participants according to predefined eligibility criteria, demographic and clinical information was recorded.Hamstring tightness was assessed using the popliteal angle test, and pelvic alignment was assessed using a bubble inclinometer according to predefined operational criteria.Frequencies and percentages were calculated to determine the prevalence of hamstring tightness and pelvic asymmetry.The association between the two variables was assessed using the Pearson chi-square test, and the odds ratio (OR) was calculated. ResultsHamstring tightness was present in 34 of 52 participants (65.4%), while pelvic asymmetry was present in 28 of 52 participants (53.8%).Among participants with hamstring tightness, 25 of 34 (73.5%) had pelvic asymmetry, compared with 3 of 18 (16.7%)participants without hamstring tightness.A statistically significant association was observed between hamstring tightness and pelvic asymmetry (χ²(1) = 15.31,p < 0.001; OR = 13.89)(95% CI: 3.2-59.5)). ConclusionHamstring tightness and pelvic asymmetry are common among individuals with CLBP, and a significant association is observed between these characteristics.Pelvic asymmetry is more frequently observed among participants with hamstring tightness.Assessment of hamstring flexibility and pelvic alignment can be considered part of a comprehensive physiotherapy examination.However, the cross-sectional design does not establish a causal relationship, and further research is needed to clarify the clinical significance of this association.