Association between muscle strength and low back pain among middle-aged and older adults: a cross-sectional study

There has been limited research examining the relationship between muscle strength and low back pain (LBP). Our study aims at investigating the association in middle-aged and older population in China.

The dataset used in this study was derived from CHARLS Wave 3. The identification of LBP symptoms relied on self-reported data. Muscle strength was measured by grip strength (determined using a handgrip dynamometer) and chair-rising time (recorded using a stopwatch). This study employed a cross-sectional design involving 10,985 final participants. Multivariate logistic regression analysis subgroup analysis, and interaction tests were used in our study to explore the potential association.

A cohort of 3871 individuals (35.2%) reported a history of LBP, displaying significantly lower levels of muscle strength in comparison to the control group (grip strength, p < 0.001; chair-rising time, p < 0.001). Multivariate regression analyses revealed a significant association between decreased muscle strength and higher risk of LBP among study participants after accounting for all potential covariates (grip strength: OR, 0.974, 95% CI: 0.970, 0.979, P = 0.010; chair-rising time: OR, 1.056, 95% CI: 1.045, 1.067, P < 0.001). Restricted cubic spline models further revealed an L-shaped relationship between muscle strength and LBP, suggesting the possible potential non-linear trends in the association. The subgroup analysis indicates that this association was consistent among different groups.

Our study revealed a significant association between weaker muscle strength and higher LBP risk, suggesting that interventions aimed at improving muscle strength may be beneficial in reducing the incidence of LBP. Further studies should address the progression of LBP and explore how muscle strength interacts with other risk factors, such as age, body mass index, and physical activity levels, to influence LBP outcomes.