Azizi, S. .; Elahi, M. .; Dadarkhah, A. .; Shirzadi, E. .; Rezasoltani, Z. .; Abdorrazaghi, F. . The Effect of Strengthening Exercises of the Hip Extensor and External Rotator Muscles on Patellofemoral Pain Syndrome. JPMRE 2019, 1, 83-90.