My hip joints have been popping/grinding when I walk for a few months now. However, I feel no pain when walking and my hip mobility is fine. I am only 18 years old so osteoarthritis doesn't seem like something I would have at my age. I'm thinking it has to do with the angle of my hips, as I am female, so my hips cause my knees to almost touch, rather than having completely straight legs like a male. I'm not sure if the sound is the cartilage grinding together, or if it is synovial fluid popping.