Hi, H.. I don't have that problem with my boys thank goodness. They have enough to deal with. I personally have flat feet and always have and it explains to me why I hate walking nowasdays but having good pair of sneakers with arch support is good, but the arch suport will wear down evenually. When I was a child, nothing hurt. My flat feet didn't both me until I got older. My legs hurts once in a while, but my feet hurts the worst and would love a massage, but the massage doesn't really do much. If your son eventually complains of his legs or that his back hurts have him stretch which we all need to do and for our children to learn too...stretch out the muscles in the thighs, hamstrings and calves. I find that if I do that after all exercises, including if I just walk, my back doesn't hurt much either. I have learned as I got older these are the things that hurt the worst and what I have learned (again, I'm much older and things may have changed in ways to help children with flat feet). If I walk or exercised, stretching the muscles keep the back, esp. the lower back from hurting so much. Make sure he squats to pick things up as he grows up, and I have found that if jump off something and land on my feet, I get this sharp pain shoot from the foot up past the ankles and it happens just when I land on my feet. So, it's a good idea now for your son to get the supported sneakers (because he's growing and buying him something that cost him an arm and a leg when he will outgrow them, but gel kind, I don't know if that will help), stretch after walking and/or exercising. I used to and still love hightops sneakers. They seem to feel good around the ankles. I felt that it was supporting and aligning my feet and my ankles. I hope that this helps you. Any more questions or anything, let me know. I'll try to help you from my experience....I'll pray for you to have wisdom from Jesus in this situation and I'll pray for you both.