The invention relates to an apparatus for the prevention and treatment of back pain, which is based on lumbar, dorsal and cervical strength training machines. The inventive apparatus comprises three vertebral supports which are disposed at a determined angle and which are used to strengthen and stretch (separation of the vertebral joints) the lumbar, dorsal and cervical areas of the back simultaneously in the appropriate movement plane. In order to prevent and treat back pain, once the back has been suitably positioned, all of the back must undergo simultaneous symmetrical strengthening. For said purpose, the apparatus consists of a vertical iron structure comprising three supports, which is perfectly articulated with a horizontal iron structure comprising a seat which can be used to perform seated exercises. According to the invention, the back is pushed against the cervical, dorsal and lumbar supports in order to produce symmetrical strengthening and stretching movements which can be adjusted to suit the individual using height and resistance control means, such as to have a decompressive effect on the vertebral column.