Putri LS, Anjasmara B, Widanti HN. Differences in Nordic Hamstring Exercise and Contract Relax Stretching on Increasing Flexibility in Students with Hamstring Tightness at Muhammadiyah University of Sidoarjo. jims [Internet]. 2023Aug.30 [cited 2024May3];50:10.21070/jims.v5i0.1571. Available from: https://jims.umsida.ac.id/index.php/jims/article/view/1571