I need to compare means between three or more groups, with dependent and related variables. If the sample has a normal distribution, the ANOVA for repeated measures statistical test is used. In this test, not only it is possible to verify the statistical significance between the tested groups, but also to study the influence of other factors. That is, it calculates the interaction between continuous variables (example: weight measured at different times) and also the influence of (one or more) ordinal variables (example: sex or age). Alternatively, if the distribution is non-parametric, the Friedman test is used. And if the Friedman test gives a statistically significant difference, it is possible to find out in which pair of groups this happens using the Wilcoxon test. However, I cannot find any non-parametric test (for related continuous samples) that allows the assessment of the statistical significance between means, while studying the influence of other factors (such as ANOVA for repeated measures that calculates the interaction between continuous and ordinal variables). Are there any tests that allow me to do this? Or will I have to perform the test for each one of the ordinal variables? Can someone help me, please. I would really appreciate it.

Best regards, AEGomes