Fortunately finding and treating trigger points is quite easy, and you don’t need an expert to do it for you. You just find tender spots which refer pain to your knee when pressed, from those muscles that are reported to be involved in knee pains.

Usually, even a few days of self-massage to those points, can make them stop referring pain to your knee area. And make it evident that they where indeed behind pain.

Finding and massaging trigger points in quadriceps and calf muscles, and small muscles behind knee (plantaris & popliteus), should give you good results.