In flat feet, foot arch is collapsed and not normal. Feet which have no arch or low arch are called flat feet. This condition is usually inherited. In sever cases, flat feet can cause back pain, calf pain, knee pain and hip pain. Treatment includes use of wide fitting shoes and high quality orthotics. For more details, visit flat feet.
Here is an article linking having flat feet to low back pain. How your feet are hitting the ground can impact the alignment of your entire body. That is why having quality shoes is a good way to treat pain and to help prevent pain. Here is a great article that can tell you more about body alignment and finding shoes that are of good quality.