Cobb angle below the fracture. The Cobb angle is the preferred method of measuring post-traumatic kyphosis in a recent meta-analysis of traumatic spine fracture classifications. Scoliosis cases with Cobb angles between 40 and 50 degrees at skeletal maturity progress at an average of 10 to 15 degrees during a normal lifetime. Cobb angles of more than 50 degrees at skeletal maturity progress at about 1 to 2 degrees per year. Those with Cobb angle of more than 60° usually have respiratory complications. Cobb angle The Cobb angle, named after the American orthopedic surgeon John Robert Cobb (1903–1967), was originally used to measure
Degrees of freedom Degrees of freedom In many scientific fields, the degrees of freedom of a system is the number of parameters of the system that may vary independently. For example, a point in the plane has two degrees of freedom for translation: its two coordinates; a non-infinitesimal object on the plane might have additional degrees of freedoms related to its orientation. In mathematics, this notion is formalized as the dimension of a manifold or an algebraic variety. When "degrees of freedom" is used instead of "dimension", this usually means that the manifold or variety that models the system is only implicitly defined.