Small studies have an important place in research. They are a starting point that can lead to larger, better studies. How and when to use data depends some on the type of study done. In the best studies there are several groups. The researcher doesn't know who gets what treatment. The patients don't know either. And there's one group that isn't treated called the control group. The control group is used for comparison.
Data can be pooled from matching studies. In this way the researchers can take the results from more than one study and combine it together. There are actual groups who base all their findings on this type of study. It's a very valid way to study problems.
Researchers can use formulas to help them choose the right number of patients or subjects for a study. This can tell them how many must be in each group to have findings that count.
It's always best to get a medical opinion before you treat yourself for neck pain. Once you know what is the problem, then you can apply treatment known to work for that problem.