Shousha, T. M.; Abo-Zaid, N. A.; Hamada, H. A.; Abdelsamee, M. Y. A.; Behiry, M. A. The Effect of Smartphone Use on Neck Flexion Angle and Hand Grip Power Among Adolescents: Cross-Sectional Study. J. Hum. Sport Exerc. 2021, 16, S883-S891.