This book first presents important research regarding the possible pathophysiological mechanisms of fibromyalgia. Current research suggests that the basis for fibromyalgia may be a modified physiology of the central nervous system, with the nature of changes in the brain directing the thinking that fibromyalgia could be a primary brain disease. Next, in order to examine the effects of complex interdisciplinary neurophysiotherapy, five girls with Rett syndrome were included in an experimental study to assess gross motor function before and after habilitation. Rett syndrome is a rare genetic neurological syndrome, affecting almost only females and leading to severe impairments in all areas of the affected persons' life, including speech, mobility, posture, digestive and pulmonary function. Subsequently, in order to study the degenerative processes of endplate chondrocytes in vitro, the authors present a relatively quick and easy protocol for the isolation of human chondrocytes from vertebral endplates. In closing, the mechanisms of the intervertebral disc degeneration and associated factors are presented, as well as short-term surgical results with microdiscectomy treatment.