If they support your feet, are comfortable and if they fit.
By he NIH trying a new drug to help reduce pain associated with sickle-cell anemia, it's an example of an "experiment".
An experiment involves a hypothesis (an educated guess as to what's going to happen) and trying out the hypothesis and finding the solution.
Evidence shows that there are certain metals in some vaccines that people who have an allergy to metals can react, which can affect them neurologically. (i’m autistic myself and was affected by a vaccine. i hope this helps.)
