Hi Flatfoot
I think that your nickname might be linked to your condition, as pronated feet are commonly a contributing factor in development of the PFPS.
Could you tell a little more about it? Was that the first time that you experienced such an exercise related pain at your knee cap, (if so) what did you do to resolve it, did you ever have any other issues with your knees or ankles in the past, what is your normal distance and level of fitness/activity?
From your description it seems that he had been using friction therapy, targeting the patella ligament. Nowadays this is considered as an "old school" approach and a vast majority of practitioners have stopped applying it, as there are much better solutions and interventions out there. Additionally, a friction therapy for patella tendon also doesn't have a reliable level of evidence in research.