Risk Factors for Idiopathic Scoliosis. Idiopathic scoliosis, the most common form, occurs most often during the growth spurt right before and during adolescence. (Between 12 - 21% of idiopathic cases occur in children ages 3 - 10 years, and less than 1% in infants.) Mild curvature (under 20 degrees) occurs about equally in girls and boys, but curve progression is 10 times more likely to occur in girls. Being taller than average at earlier ages may put some girls at risk, but other factors must be present to produce scoliosis. A risk factor that affects females is delayed onset of menstruation, which can prolong the growth spurt period, thus increasing the possibility for the development of scoliosis.
Risk Factors for Curvature Progression. Once scoliosis is diagnosed, it is very difficult to predict who is at highest risk for curve progression. About 2 - 4% of all adolescents develop curvature of 10 degrees or more, but only about 0.3 - 0.5% of teenagers have curves greater than 20 degrees, which requires some medical attention.
Medical Risk Factors
People with certain medical conditions that affect the joints and muscles are at higher risk for scoliosis. These conditions include rheumatoid arthritis, muscular dystrophy, polio, and cerebral palsy. Children who receive organ transplants (kidney, liver, and heart) are also at increased risk.
Scoliosis may be evident in young athletes, with a prevalence of 2 - 24%. The highest rates are observed among dancers, gymnasts, and swimmers. The scoliosis may be due in part to loosening of the joints, delay in the onset of puberty (which can lead to weakened bones), and stresses on the growing spine. There have also been isolated reports of a higher risk for scoliosis in young athletes who engage vigorously in sports that put an uneven load on the spine. These include figure skating, dance, tennis, skiing, and javelin throwing, among other sports. In most cases, the scoliosis is minor, and everyday sports do not lead to scoliosis. Exercise has many benefits for people both young and old and may even help patients with scoliosis.