Your feet are the foundations of your body. They can absorb up to three or four times your body weight with every step that you take. If these foundations are not solid and stable, then the function of your entire body will be affected. There are two foot types that cause faulty or unstable foundations for the body - they are extremely low arched feet (flat or pronated feet) and extremely high arched feet (high arched or supinated feet).
High arched feet can cause pain in your back due to their inability to absorb shock. High arched feet don't roll in when they're supposed to (when the foot hits the ground), making them rigid and unable to absorb the shock of walking and running effectively, causing jarring and instability to your back.
Any abnormalities within the foot when it hits the ground, with up to four times your body weight, becomes magnified and is then transferred to your knees, back and even your neck and head. People with high arched feet can be prone to disc pain in their back, and even headaches or migraines after long periods of walking.
If you have flat or pronated feet, you legs rotate internally and your pelvis rotates anteriorly, creating mal-alignment of the base of the sacro-iliac joint and lumbar spine with resultant muscle imbalance and low back strain.