Archies Thongs are great for people with foot issues such as accessory navicular. The arch support helps to support the foot in a more optimal position and the foam helps provide support and cushioning.
One of the other key designs to point out with Archies Thongs is they have a tighter toe strap which reduces toe clawing. The problem with regular flat thongs, they are often heavy and have loose straps, your foot and toes have to work or "claw" to keep the thongs on your feet. This can lead to tired, achy feet at the end of the day and long term overuse injuries to your tendons (inc Plantar Fasciitis).
Our Archies Thongs however have a tighter strap, so they hold onto your foot rather than the other way around. Plus they are extraordinarily light in comparison to regular thongs.