There are many diferent causes for back pain, however the main cause is simply poor body posture... Poor posture when sitting in front of a computer or watching TV on the couch are very, very common. Also, many of us have poor posture when standing up-right, gradually worsening over longer periods of standing. Most people are not aware of their poor body posture, so correcting it is not that easy.
Interestingly, bad body posture can often be contributed to problems at the feet! When the feet over-pronate (roll inwards), it can put the entire body out of balance!
Typically, over-pronation causes the legs to rotate inwards and the pelvis to tilt forward. The result is increased spinal curvature and continuous tension on the muscles in the lower back causing pain and discomfort.
Therefore, most people who suffer from low back pain, especially after standing for longer periods, or walking long distances, should consider their feet as a likely cause..