Association between ClinFIT, pain, disability, and spinal mobility in patients with chronic nonspecific low back...

The aim of this study was to evaluate changes in functioning during rehabilitation using ClinFIT and to identify baseline predictors of post-treatment functional status. In this prospective single-arm pre-post study, 123 patients with cLBP (mean age 51.8 ± 9.1 years) completed a standardised 4-week physiotherapy programme. Participants were assessed at baseline, mid-treatment, and post-treatment. Functioning was measured with ClinFIT, disability with RMDQ, pain intensity with VAS, and spinal mobility with the Schober, reclination and Thomayer tests and sagittal mobility index. Changes over time were assessed with Friedman tests. Hierarchical multivariable linear regression identified independent predictors of post-treatment ClinFIT scores, controlling for age, sex, and BMI. All outcomes improved significantly during treatment (all Friedman tests p < 0.001; Kendall's W 0.18-0.52). ClinFIT correlated moderately with RMDQ (ρ = 0.54-0.62) and VAS (ρ = 0.48-0.56), and only weakly with objective spinal mobility measures (Thomayer ρ = 0.26-0.32; Schober correlations were non-significant). In the final multivariable regression model (R² =0.616, adjusted R² =0.578, p < 0.001), baseline ClinFIT was the strongest predictor of post-treatment functioning (β = 0.67, p < 0.001). Baseline RMDQ, age, sex, BMI, employment status, disease duration and objective mobility measures were not significant independent predictors. Patients with cLBP improved significantly in functioning, pain, disability, and spinal mobility over the rehabilitation period. Baseline functional status was the strongest predictor of post-treatment functioning, although this partly reflect the use of the same instrument at both time points. Objective mobility measures showed limited independent value. ClinFIT appears to be a promising tool for monitoring functioning in rehabilitation settings.