We conclude that assessing objective and subjective data obtains the most accurate measures of mobility. To obtain objective data, objective measures of mobility will be opposed to pedometers and accelerometers, while questionnaires were selected for subjective data due to its ease of use and sociodemographic data that provides. Among these instruments, the Short Physical Performance Battery (SPPB) and Minnesota Leisure Time are the most appropriate instruments to estimate the mobility of the elderly in Spain.