That’s any point really. Again, though, not all will do that regardless of the activity at a particular point. A more useful way to get this information is what is called palpatory diagnosis, which we use extensively, but that is beyond what can be easily described in an online forum as it requires deeper training in the internal arts (tai chi, meditation, etc.) as well as comprehensive understanding and practice experience with Chinese Medicine. Suffice it to say all the points can provide a skilled practitioner with helpful information and redness is one of many possible ways this can be communicated by the body.