Confirmatory factor analysis of the Arabic version of the Lower Extremity Functional Scale.

The aim of this study was to examine the factorial structure of the Arabic version of the Lower Extremity Functional Scale (LEFS-Ar) using a confirmatory factor analysis. The study was designed as a cross-sectional study in which individuals with lower extremity musculoskeletal disorders were recruited. During the testing session, participants completed the LEFS-Ar in addition to general information form and anthropometric measurements. A hypothesized one-factor structure underlying the 20 items of the LEFS-Ar was examined using a confirmatory factor analysis. The fit of the observed data to the hypothesized factorial structure was examined using multiple fit statistics including χ2, Tucker-Lewis index (TLI), comparative-fit index (CFI), and the root mean square error of approximation (RMSEA). A total of 160 patients with lower extremity dysfunctions participated in this study. The fit statistics showed the following: χ2 goodness fit statistic=654.390 (d.f.=170, P<0.001), TLI=0.754, CFI=0.78, and RMSEA=0.134 (90% CI=0.123-0.145). These fit statistics indicate that the data do fit the one-factor structure proposed in this study. Examination of standardized residuals and modification indices pointed to areas of misfit within the model. The findings of the current study do not support the hypothesized one-factor structure of the LEFS-Ar and suggest that modifications are needed to the LEFS-Ar to yield a unidimensional measure of lower extremity function (i.e. activity limitation due to lower extremity dysfunction).