Hips are another ball and socket joint that is connected to the pelvic girdle. It serves as a very important structure in weight acceptance. Large muscles that surround the hip joint are meant to be massive, to give you both stability and to produce powerful movements in walking and running. If the muscles around the joint are not strong enough to accept multiple times your body’s compressive loads, the stress is distributed to your lower back, higher up your back, as well as down to your knees.