Question for PTs...

What causes a person to keep developing trigger points in leg muscles? I had some (peroneus longus/brevis, and also somewhere in the medial part of the calf) that started as a result of compensating for other injuries but those original ones seem to have gone away or at least nearly so after being very diligent with the Stick and stretching for a couple of weeks. However, now I have developed some more in other muscles over the past week (vastus medialis and somewhere in the outside of the calf about 2/3 of the way up); they don't seem to be radiating that much (though I think the knee twinges I've had on my last couple of runs were probably from the VM) but they do hurt like you-know-what when pressed on. My question is, why do they keep popping up and how can I stop that from happening? I had never experienced this sort of thing before but I think the IT band problem and also a case of "lace bite" on my left foot from my hiking boot (which was really painful for a couple of weeks and still isn't 100%), plus being on my feet constantly between work and clinical, must have kicked off a whole chain reaction. Would stress and sleep deprivation contribute? This semester in school has been filled with both. Any info would be appreciated!