en Nursing Original Article <div style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Times New Roman;"><b>Background:</b> Headache is common in multiple sclerosis and is associated with greater functional disability. We aimed to determine whether a structured progressive muscle relaxation (PMR) program reduces headache-related disability in multiple sclerosis.<br> <b>Methods:</b> We conducted a parallel-group, quasi-experimental pretest&ndash;posttest study at Multiple Sclerosis Society clinics in Zahedan, Iran (2023). Adults with MS and recurrent headaches were allocated to PMR (n = 30) or usual care (n = 30). The PMR intervention comprised three 20 - 30-minute group sessions on consecutive days plus daily home practice for six weeks; adherence was supported by weekly phone calls. The primary outcome was the Headache Disability Inventory (HDI; 0 - 88), measured at baseline and at 3-month follow-up. Analyses were conducted using SPSS version 24 and employed &chi;&sup2; tests and ANCOVA, adjusting for baseline HDI and disease duration (&alpha; = 0.05).<br> <b>Results:</b> Sixty participants completed the trial (30 in the PMR group and 30 in the control group). The groups were comparable in age and gender at baseline; however, disease duration was significantly longer in the PMR group (p = 0.014). At the 3-month follow-up, HDI scores showed a significant decrease in the PMR group (21.5 &plusmn; 15.6) and a significant increase in the control group (45.1 &plusmn; 16.9), resulting in a significant between-group difference (p < 0.001). An analysis of covariance (ANCOVA), controlling for baseline HDI scores and disease duration, confirmed a significant treatment effect (F = 25.07, p < 0.001) with a large effect size (partial &eta;2 = 0.305).<br> <b>Conclusion</b>: A six-week progressive muscle relaxation program significantly reduced headache-related disability at 3-month follow-up in multiple sclerosis and appears to be a feasible, low-cost adjunct to routine care. Larger randomized trials with longer follow-up and objective adherence tracking are warranted.</span></span></div> Multiple sclerosis, Progressive muscle relaxation, Quasi-experimental, Non-pharmacological, Headache Disability Inventory, Disability 34 39 http://nmj.goums.ac.ir/browse.php?a_code=A-10-2213-1&slc_lang=en&sid=1 Mahdi Rezvaniamin mehdi.rezvaniamin@gmail.com 100319475328460016976 0009-0008-3886-1478 No Community Nursing Research Center, School of Nursing and Midwifery, Zahedan University of Medical Sciences, Zahedan, Iran Alireza Salar salar293@gmail.com 100319475328460016977 100319475328460016977 Yes Community Nursing Research Center, School of Nursing and Midwifery, Zahedan University of Medical Sciences, Zahedan, Iran Zahra Pournamdar zahrapournamdar@yahoo.com 100319475328460016978 100319475328460016978 No Community Nursing Research Center, School of Nursing and Midwifery, Zahedan University of Medical Sciences, Zahedan, Iran Nazanin Yousefian n.yoosefian@yahoo.com 100319475328460016979 100319475328460016979 No Community Nursing Research Center, School of Nursing and Midwifery, Zahedan University of Medical Sciences, Zahedan, Iran