Safikhani, Hassan, Tengku Fadilah Bt Tengku Kamalden, Saidon Bin Amri, and Megat Ahmad M.M.H. “The Effect of Different Systems of Carrying Backpacks on Muscle Activity”. Journal of Human Sport and Exercise 10, no. 2proc (September 27, 2021): S692-S698. Accessed April 20, 2024. https://www.jhse.ua.es/article/view/2015-v10-n2-proc-the-effect-of-different-systems-of-carrying-bac.