Scoliosis to 3% of individuals. The age of onset is usually between 10 years and 15 years (can occur at a younger age) in children and adolescents, making up to 85% of those diagnosed. This is seen to be due to rapid growth spurts occurring at puberty when spinal development is most relenting to genetic and environmental influences. Because female adolescents undergo growth spurts before postural musculoskeletal maturity, scoliosis is more prevalent among females. Although fewer cases are present today using Cobb angle analysis for diagnosis, scoliosis remains a prevailing condition, appearing in otherwise healthy children. Incidence of idiopathic scoliosis (IS)
Supernumerary body part considered to have lost much or all of their original function through evolution. These body parts can be classed as additional to the required functioning of the body. In human anatomy the vermiform appendix is sometimes classed as a vestigial remnant. Prosthesis is an artificial extension that replaces a body part, and cybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts. Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms