“Validity of the Sit and Reach Test for Hamstring and Low Back Flexibility: A Systematic Review”. COMPETITOR: Jurnal Pendidikan Kepelatihan Olahraga 18, no. 1 (February 1, 2026): 0013–0025. Accessed February 1, 2026. https://competitor.idjournal.eu/index.php/competitor/article/view/468.