If you've got super-flat feet - you may want to consider taking up ice skating, skiing, or rollerblading!!
Think about it this way: if you come into my office with a broken bone in your foot, I put you in a cast. A cast, because it allows no motion across the site of the fracture, eliminates pain, inflammation, and swelling and allows the fracture to heal.
If you have a super-flat foot - doing normal activities (even in the best of shoes and inserts) may cause foot, ankle, knee, and leg pain due to "biomechanical strain" of your foot trying to stabilize your body.
By placing yourself in a ski or ice skating "boot" - you are in effect putting your foot into a "cast" which will significantly limit motion so that you can perform the sport with minimal or no pain.
Over the years, I've noticed that many of my patients with severe hypermobility (super-flexible feet) and flat feet have tended toward what I call the "winter sports."
Special Note: Custom-molded orthotics can be made specifically for ski and ice skating boots but, if they are not covered by insurance or too costly to purchase out of pocket for a quickly growing child, a good over-the-counter insert or heat-molded insert will work very nicely.
If you have a child who has severe flat feet and they are inactive - try getting them into one of these activities!! They may love it and it could lead to a more active and healthy lifestyle.
**One thing they stressed in our pediatric podiatry classes, if your child is complaining of foot and ankle pain, take them to your podiatrist to get a evaluation and treatment! Kids may fake stomach aches and coughs to get out of school but, trust me on this, they don't fake foot pain. Weird but true...
Hope all is well!