Pain in the side or back of the hip is commonly associated with lower back pain, as well as conditions that change the way you walk. For instance, a sore foot or knee that you are favoring can lead to secondary problems higher up.
Hip and Rear End Pain
Rear End pain
Pain in the gluteal region can come from overt injuries, like slipping and falling onto your bottom, or can be associated with other nearby problem areas such as the lower back.