Sometimes when I am standing or walking my left hip and leg give way and it's painful to staff on my leg for a few minutes it feel like my hip is out of place this has been happening on and off for the past 3 years. Now I have found a lump in my lower back to the right just about my butt cheek which you can feel when you press in and is becoming quite tender, it feels like a raised bone or muscle. Anyone have an idea what it may be?