Tehran University of Medical Sciences Journal of Modern Rehabilitation 2538-385X 18 2 2024 01 23 262 275 Raghad Khazraji Department of Physical Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Siamak Bashardoust Tajali Department of Physical Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Kazem Malmir Department of Physical Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Ali Al-Hafidh Department of Physical Therapy, Rheumatology and Medical Rehabilitation, School of Rehabilitation, College of Health and Medical Technology, Baghdad, Iraq. 2023 03 18 2023 06 11 Introduction: Pes anserine bursitis (PAB) is a painful status inside the knee that may interfere with functional activities. Extracorporeal shockwave therapy (ESWƬ) may treat this disorder. Objective: Comparing the effects of low- versus middle-energy ESWƬ on pain and functional activity in patients with sub-acute PAB. Materials and Methods The study was a single-blind randomized trial. Twenty-eight patients with sub-acute PAB were randomly divided into two groups and received either low or middle-energy ESWƬ for three weeks. The numeric pain rating scale (NPRS), short-form McGill pain questionnaire (SF-MPQ), timed up and go (TUG) test, and Western Ontario and McMaster universities index (WOMAC) were evaluated before and 2 and 3 weeks after the intervention. Results: A significant improvement was observed for low-energy ESWT in terms of NPRS (P=0.001), SF-MPQ (P<0.001), WOMAC (P<0.001), and TUG (P<0.001) 3 weeks after the intervention. Also, a significant improvement was observed following middle-energy ESWT application on NPRS (P=0.003), SF-MPQ (P<0.001), WOMAC (P<0.001), and TUG (P<0.001) 3 weeks after the intervention. A similar trend was observed between study time points and for all variables in each group. The only exception was the TUG, which showed no improvement between 2 and 3 weeks after the intervention for each study group. A significant improvement was observed in the NPRS between the two groups after 2 weeks (P=0.001) and 3 weeks (P=0.006), both favoring the middle-energy ESWT application. Conclusion: Low- and middle-energy ESWT can effectively improve pain, functional activity, and mobility in patients with PAB. https://jmr.tums.ac.ir/index.php/jmr/article/view/859