RESUMO
BACKGROUND: Muscle Force (MF) and amplitude of active movement (AAM) are progressively affected in amyotrophic lateral sclerosis (ALS). These measurements are correlated with mobility but influence it in a distinct manner. OBJECTIVE: To determine the influence of MF and AAM on the mobility of the subjects with ALS. METHODS: The formula for identifying the covariables and scale of mobility of the Amyotrophic Lateral Sclerosis Assessment Questionnaire were applied to 23 subjects with ALS. The MF data of the knee and ankle flexors and extensors were collected in the most affected limb. In conjunction, the AAM of hip and knee flexion were captured. Multiple linear regressions were used, considering alpha ≤0.05. RESULTS: MF and AAM interfered in mobility and are responsible for 63.6% of the variation in mobility. The variable that explained this variation was the AAM of hip flexion. The stage of disease was considered a covariable. CONCLUSION: AAM of hip flexion is a safe predictor of mobility in ALS. Retarding loss of this AAM may maintain these subjects functional for a longer time. It was not possible to use MF of the muscles evaluated to predict mobility.