Tehran University of Medical Sciences Journal of Modern Rehabilitation 2538-385X 16 3 2022 07 01 235 243 Aysha Rani Khan Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia, New Delhi, India. Kritika Sethi Department of Physical Rehabilitation and Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Majumi M. Noohu Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia, New Delhi, India. 2021 03 31 2021 07 10 Introduction: This study aims to evaluate the effect of modified hold-relax stretching combined with moist heat therapy on hamstring muscle flexibility, EMG activity and strength in college students with hamstring tightness. Materials and Methods: Thirty-eight college students with hamstring tightness were recruited and were divided into two groups. Group 1 received modified hold-relax stretching plus moist heat therapy and Group 2 received moist heat therapy alone, three days a week for four weeks. The knee range of motion (ROM), muscle strength and Electromyography (EMG) activity before and after the treatment protocol were measured. Results: There was no significant difference between the two groups in demographic characteristics. The knee ROM was significantly different between groups in terms of time (P=0.001) and group (P=0.005) effects, but the strength and EMG activity were not significantly different. Conclusion: The modified hold-relax technique combined with moist heat therapy is effective in increasing hamstring flexibility, but has no significant effect on the muscle EMG activity and strength. https://jmr.tums.ac.ir/index.php/jmr/article/view/411