Cuboid syndrome is a reasonaly common problem affecting the function of the cuboid bone and the joints around it. It is a common casue of lateral foot pain. Manipulation of teh cboid bone is a common treatment.
Calcaneal Apophysitis is also called Severs Disease and is a common condition of the growth plate at the back of the heel bone in kids. It is most commonly treated with a cushioned heel raise and is a self limiting problem that eventually comes right by itself.
Ankylosing Spondylitis is primarily a problem of the spine, but the arthritis there can also cause arthritis in the foot and pain in the heel. The involvement of the spine also means the feet are going to be difficult to reach to provide self care for foot problems.
This is something of a legend that happened in Australia where a footballer with a chronic plantar fasciitis allegedly jumped from a height in order to rupture his plantar fascia to facilitate healing. A surgical cutting of the plantar fascia is often used to treat chronic plantar fasciitis. It apparently worked.
Severs disease or calcaneal apophysitis is a common problem causing pain in the heel of kids; it is an overuse type injury to the growth plate at the back of the heel bone. It is a self limiting problem that always comes right eventually when the growth in the heel bone stops. Several treatments have been advocated for it treatment. One of these is a dietary supplement called Oscon which consists of selenium and vitamin E. It is only supported by the use of testimonials and no clinical study has been done on it. It is not clear if it is worth trying or not as most children do get the minimum dietary requirements for Vitamin E and Selenium from their normal daily intake.