Hi Sam,
I am a physical therapist and I have had more than a few patients lately with your problem. We have had better luck with less mob work with the bands when your symptoms have occured.. Unfortunately if you have an ugly arthritic knee, the bands will not change the joint surfaces. The return of knee pain and swelling or stiffness is not an optimal response to the use of the bands..You could have your knee examined by your orthopedic specialist to see if any other treament may be needed. Try to train around you pain and do activities that don’t bring on those symptoms. Making a joint hurt is never a good idea! Hope it gets better.

Tim Daley PT