Physical activity or spine deformity: which factor matters most for pain intensity in adults with idiopathic scoliosis? A cross-sectional study.

PURPOSE: To evaluate whether current pain intensity in adults with idiopathic scoliosis is associated with scoliosis curve magnitude and physical activity practice.

METHODS: This retrospective cross-sectional study included adults aged ≥18 years with idiopathic scoliosis, defined as a Cobb angle ≥10°. Current pain intensity, assessed using the 0-10 numerical rating scale, was the dependent variable. The main independent variables were largest Cobb angle and physical activity practice, coded as yes versus no. Multivariable linear regression was used to examine associations, adjusted for age, sex, and BMI. Heteroscedasticity-consistent robust standard errors were estimated using the HC3 estimator.

RESULTS: We included 474 adults with idiopathic scoliosis (median age 28 years; 81% female). Median largest Cobb angle was 39°, and two-thirds of participants reported practicing physical activity, most commonly strength training, aerobic exercise, and Pilates. Median pain intensity was 4.0 (IQR 0.0-6.0). Largest Cobb angle was not associated with pain intensity (β = 0.00, 95% CI - 0.01 to 0.02). In contrast, adults who practiced physical activity reported, on average, 0.99 points lower pain intensity than those who did not, after adjustment for Cobb angle, age, sex, and BMI (β = - 0.99, 95% CI - 1.61 to - 0.37).

CONCLUSION: Pain intensity was not associated with scoliosis curve magnitude. Physical activity practice was associated with approximately 1-point lower pain intensity, suggesting that pain in adults with idiopathic scoliosis may be less closely related to structural deformity and more consistent with modifiable lifestyle factors.