Scoliosis are "captured", meaning that they are held fast between the ilium bones of the pelvis. Compared to humans, Old World monkeys have far larger erector spinae muscles, which are the muscles which hold the spine steady. These factors make the lumbar spine of most primates less flexible and far less likely to deviate than those of humans. While this may explicitly relate only to lumbar scolioses, it is possible that small imbalances in the lumbar spine could precipitate thoracic problems as well. Scoliosis may be a byproduct of strong selection for bipedalism. For a bipedal stance, a highly mobile, elongated
Neuromechanics of idiopathic scoliosis Besides, idiopathic scoliosis being more frequent in certain families, it is suspected to be transmitted via autosomal dominant inheritance. Estrogens could also play a crucial part in the progression of idiopathic scoliosis through their roles in bone formation, growth, maturation and turnover. Finally, collagen, intervertebral disc and muscle abnormalities have been suggested as the cause in idiopathic scoliosis, although these are perhaps results rather than causes. The patient’s age at presentation of scoliosis, the remaining growth, the menarche status and the magnitude of the curve are used to foresee the idiopathic scoliosis curve progression. However, the relative importance of each