Cobb angle measurement of a<unk> ; concave side on the left; convex side on the right Vertebra and curves of the vertebral column Cobb angle is a common measure to classify<unk> . The greater the angle, the more serious is the disease but the smaller is the number of patients. One to three out of every hundred people have<unk><unk>  curves greater than 10° with an equal proportion of boys and girls. One to three out of every thousand people have<unk><unk>  curves greater than 30° with a ratio of eight girls for every one boy.<unk>  is also classified according to the region(s) they affect. The vertebral column can be deformed at the thoracic level, at the lumbar level or at both. In the lumbar region,<unk>  induces perturbations to standing balance. The thoracic region is the location that most impacts movement strategies.<unk>  impedes on the movement of the ribs, places the respiratory muscles at a mechanical disadvantage and displaces the various organs of the thoracic cavity. Skeleton In a scoliotic patient, the vertebral column experiences extension forces on the convex side and compression forces on the concave side. At the apical vertebra, average bone density for the concave cortical bone is higher than for the convex cortical bone, and cancellous bone density is higher for the concave side than for the convex side. The concave side of a vertebra is less porous and has a thicker cortical bone than the convex side, which is consistent with Wolff's law about bone remodeling. Muscle Scoliotic adolescents, at the apex vertebra, have a higher muscle activity (as measured by surface electromyography) on the convex side than on the concave side in sitting or standing conditions. Because in scoliotic people wearing a brace, the muscle activity of the erector spinae muscles decreased on the convex side when walking with the brace and because after spinal arthrodesis surgery,<unk>  scoliotic people showed a significant decrease in paravertebral muscle activity on the convex side but not on the concave side, the muscular asymmetry in<unk><unk>  is thought to be a biomechanical consequence of the scoliotic curvature rather than its cause.
Neuromechanics of idiopathic scoliosis
Passive physiological intervertebral movements
Range of motion
Radiographic classification of osteoarthritis
Range of Motion
Passive accessory intervertebral movements
Joint stability
Chiropractic treatment techniques