Relationship between hip flexor tightness and low back pain in non-care-seeking individuals

Low back pain (LBP) is a prevalent musculoskeletal condition with significant economic consequences (Wu et al., 2020). Despite evidence of functional limitations, non-care-seeking individuals with LBP remain an under-researched population (Vraa et al., 2022). Hip flexor tightness has been proposed as a potential contributor to LBP due to its role in altered biomechanics and compensatory lumbar movements (Kim & Shin, 2020). Tight hip flexors are frequently assumed to contribute to LBP, yet the nature of the relationship is unclear. The objective of this study was to examine the relationship between hip flexor tightness and LBP severity in individuals with and without LBP who have not sought medical care.

A cross-sectional study of 118 adults (aged 20-61) assessed hip flexor range of motion (ROM) using the Modified Thomas Test and low back pain severity using the Modified Oswestry Disability Index. Between-group comparisons and generalized linear models examined the relationship between ROM, LBP presence, and disability.

LBP participants had significantly reduced ROM (4 ± 9° vs. 8 ± 9°, p = 0.003). However, in the adjusted generalized linear model, only BMI remained a significant predictor of hip flexor ROM (p = 0.011), while LBP status was not independently associated with hip flexor ROM (p = 0.180).

Reduced hip flexor ROM was observed in non-care-seeking individuals with LBP but was not independently predictive after adjustment. BMI was the only significant factor associated with hip flexor ROM, underscoring the multifactorial nature of LBP.