These rigid carbon inserts are used to stiffen the shoe in cases of hallux rigidus, first MPJ osteoarthritis, Turf toe, midfoot osteoarthritis and other conditions of the foot that are painful on movement. These rigid inserts make the shoes stiffer and restrict movement.



You can buy these here:
https://www.footstore.com.au/hallux-rigidus-insoles/
https://podiatrydeals.com/
https://carboneaze.com/