Flat feet will exempt you from the draft, but that is where are their benefit stops. This condition can be inherited, but the arch can also fail to develop during puberty.
The entire bottom of the foot will contact the ground when walking if you have flat feet.
Overpronation happens when the way you walk causes the arches of the feet to flatten even more, putting a strain on the muscles, tendons, and ligaments that support your arches. Overweight and running a lot on hard surfaces accentuates this problem, and pain in the ligaments in the arch of the foot is the result.
Overpronation may be indicated by excessive wear on the inside of the heels and soles of your shoes, and can cause all kinds of problems such as Achilles tendinitis, iliotibial band syndrome, plantar fasciitis, shin splints, and even knee, hip, or back pain. these things may develop in compensation to overpronation while walking.
As an older person, I have pretty much given up tennis and running, and walk rapidly for long (for me) distances in order to get sufficient exercise. Without noticeably increasing my walking, I have recently developed tenderness in the arch of my left foot that made walking painful. Curling my toes, and walking on the outside of my feet seemed to alleviate the pain. This is an exercise that I remember from my childhood, and may have been shown me because of my moderately flat feet.
Swimming for Exercise, and decreasing the amount of walking seems to have corrected the condition at least temporarily, but I have also ordered some orthotic inserts for my shoes as an arch support, in case I need them going forward. I have been told that if this is insufficient I can go to a specialty store and order some special shoes that might help. I have not mentioned painkillers such as NSAIDs, because I try to avoid them
Please check with the accompanying references for more information about flat feet and over pronation.