“ Reference Values of Ultrasonographic Measurement of Cross-Sectional Area of the Multifidus Muscle in Children Aged 6 to 9 Years ”. Fisioterapia e Pesquisa 22, no. 2 (June 6, 2015): 176–181. Accessed April 23, 2025. https://revistas.usp.br/fpusp/article/view/103934.