The ball of the foot is known as the metatarsophalangeal joint (MTPJ) region. The long bones of the forefoot (metatarsals) and the toes (made up of phalanges) form the MTPJ’s.
Metatarsalgia is a ‘catch all’ term used to describe pain in this region (algia = pain). It is therefore not a diagnosis in its own right as there are many conditions that can cause pain in this region. The more common are listed in the related conditions.