This paper discusses some of the main methodological challenges involved in carrying out research on pain, especially pain experienced by people with multiple sclerosis (MS). It starts by arguing the most common challenges in pain related research methodology, which will form the framework of this article. Within this framework, the issues include pain definition, the self-reported nature of pain, the complex and multidimensional nature of pain, confounders, study design, and other methodological challenges faced by researchers in using assessment tools and scales. Presenting a universal framework for pain measurement, suggesting appropriate study design, and using comprehensive assessment and appropriate statistical method to analyze the collected data will be the main solutions for those challenges that are discussing at the end of this paper. Finally, paper will end with a conclusion of study's implications and significance.

Introduction: Joint pain, especially pain in the knee joint, is one of the most important problems that people with osteoarthritis report.The aim of this study was to determine the effects of resistance training with theraband on pain and quality of life in patients with knee osteoarthritis.
Materials and methods: Twenty five patients with knee osteoarthritis with age range of 38 to 65 years’ old who had no history of any exercise during the past six months, and had no chronic conditions affecting on study outcomes were selected as study sample and randomly divided into two groups including experimental (n = 13) and control (n = 12) groups. The experimental group performed 8 weeks of resistance training, and the control group did not receive any intervention. SF-36 and Numeric pain rating scale were used to assess quality of life and pain, respectively. Finally, data were analyzed using SPSS software and independent t-test analysis. The level of significance was considered to be equal or less than 0.05.
Results: The results of this study showed that after using intervention in the experimental group pain had a significant decrease compared to the control group (p=0.012). Also, eight weeks of intervention indicated a significant difference in the quality of life of patients with knee osteoarthritis between the control and experimental groups as it was increased in the experimental group compared to the control group(p=0.001).
Conclusion: The findings of this study indicated that resistance training with theraband can reduce pain and enhance quality of life in patients with knee osteoarthritis.

Abstract
Introduction: Decreased physical activity is one of the main causes of the obesity epidemic. In the process of obesity, the secretion of some hepato-adipokines increases and causes metabolic disorders. Exercise plays an important role in improving the complications of obesity by regulating the levels of selected hepato-adipokine. The purpose of this study was to examine the effects of three types of resistance training methods on selected hepato-adipokine and lipid profiles in men with obesity.
Materials and Methods: The sample of the study included 44 sedentary men with obesity divided into 4 groups of traditional resistance training (TRT), circuit resistance training (CRT), and interval resistance training (IRT) as well as one control group. Fetuin-A, Fetuin-B, high-density lipoproteins (HDL), low-density lipoproteins (LDL), total cholesterol (TC), and triglyceride (TG) were measured using the ELISA method.
Results: The results of the mixed model ANOVA analysis showed a significant interaction between the type of training used and time at the levels of Fetuin-A (F (1, 40) = 94273.16, P = 0.001, ES = 1.00) and Fetuin-B (F (1, 40) = 49697.67, P = 0.001, ES = 0.99. In addition, within-group comparisons showed that lipid profile improved in TRT and CRT groups compared to the pretest (P = 0.001), while in the IRT group this improvement was not significant (P > 0.05).
Conclusion: The result of the present study shows that three models of resistance training reduced the select hepato-adipokines level in comparison to the control group. However, IRT and CRT had the greatest effect on reducing Fetuin-A and Fetuin-B, respectively.