[Cross-cultural adaptation and Argentine validation of the Lower Extremity Functional Scale Questionnaire]

The Lower Extremity Functional Scale (LEFS) is a self-report questionnaire created to evaluate a patient's functional status in a wide spectrum of lower extremity musculoskeletal conditions. Thus far, there is no valid version in Argentina. The aims of this study were to translate the LEFS, cross-culturally adapt it for use in the Argentine population, and validate it in our country by determining its psychometric properties in patients over the age of 18 with lower extremity musculoskeletal conditions, comparing it with the SF-36 and the following functional tests: step test and timed up and go. One hundred and thirty three patients were included between July 2010 and January 2012. The test-retest reliability was high, with an ICC of 0.91 (95% CI 0.85 - 0.94). The correlation of the LEFS with the physical functioning subscale and the physical component summary score of the SF-36 was high (p < 0.001) and showed moderate response with the timed up and go and step test at the baseline (p < 0.001). This version of the LEFS is a valid, reliable tool used in Argentina to measure functional status in patients with lower extremity musculoskeletal conditions that we recommend for future clinical research projects and daily clinical use.