The common physical therapy understanding of pain doesn't take into account trigger points. So any muscular dysfunction is viewed as a muscle "weakness" and the solution is then to strengthen particular muscles that appear "weak". However, that is an oversimplification and that model fails many people. Muscles can test weak just because they have trigger points or are in relationship to muscles that have trigger points. If one attempts to strengthen muscles with a high percentage of trigger point fibers, it most often fails, because there aren't enough healthy fibers to respond appropriately to the demand.