In random allocation, in order to select individuals and assign them to the two groups of control and intervention, three steps of access sampling, class allocation, and simple random allocation are respectively performed. To do this, first, people with osteoarthritis referred to the clinic and met the inclusion criteria are selected by available sampling. Since, in some cases, despite the application of stochastic programming, there is the possibility of heterogeneity in some initial features in the groups, the effective variables are excluded using the classification method. In this study, age and sex are very important factors in observing education; thus, to ensure the equal distribution of the two variables in the control and intervention groups, people with entry criteria are divided into four, men, women and 50 >, <50 years based on gender and age . Then, the samples divided into each class by a simple randomization method using the Randomization.com website, available to researchers for free, fall into intervention and control groups. For example, in women with age >50, a list of random sequences such as the following is generated, and then, people are divided into two groups of intervention and control based on their number.
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