Prevalence of low back pain in the elderly population: a systematic review - Souza, Ingred Merllin Batista de; Sakaguchi, Tina Fujii; Yuan, Susan Lee King; Matsutani, Luciana Akemi; Santo, Adriana de Sousa do Espírito; Pereira, Carlos Alberto de Bragança; Marques, Amélia Pasqual (Clinics, 2019)