If you join a Meetup.com activity, let’s say a hiking group, and you hear the members giving out impromptu advice regarding survival, health, injury, etc., make sure you consult a professional, too, or at least do some reading.
You might find that at a monthly hikers’ meeting, an attractive know-it-all is showing you a stretching exercise for your sore knee. But if you go to a good physiotherapist, you might learn that the stretching will only exacerbate your knee or hip injury, that what you really need to do is build muscle strength in the injured area.