boys, the problem is in your BACK.
This above... i have same problems, it coming from the back and then radiates to the hip or hips depending on the back issues. arthritis and compressed disk all cause this. my best bet is the following>
1 see a chiro at least 1-2 times a months to keep hips and back aligned. lots of flax and fish oil along with krill oil, and dont forget large does of vitamin D. additionally i bought a tens device that does wonders for my back and hip if they tighten up, it relaxes the tightness and soreness. if you're interested in the one i got shoot me a PM and i'll send you the link. its great and does 4 pads so it can do both hips ans both sides of lower back.