1st thing which comes to miind is overactive hipflexors. In your case likely Psoas. This muscle ought to pull the Illiops out of the way of the joint. In case of a slight impinchment of the capsula of the hip joint (which should be prevented by the Psoas). This can cause anterior hip pain. Test: hipflexor length. In case of hypertone hipflexors should investigate in pelvis aligment (well actually hypertone muscles pulling the pelvis out of position) and Low back problems. After my opinion these sort of problems seem to coincide with poor gluts strength, tight piriformis, tight hamstrings (less than 80% hipflexion).
Hopes this helps. Understand that i have just pointed out some possibilities.