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 (physics and chemistry) for 3 degrees of freedom. In addition, the molecule has two rotational degrees of motion and one vibrational mode. The rotations occur around the two axes perpendicular to the line between the two atoms. The rotation around the atom–atom bond is not a physical rotation. This yields, for a diatomic molecule, a decomposition of: For a general, non-linear molecule, all 3 rotational degrees of freedom are considered, resulting in the decomposition: which means that an -atom molecule has vibrational degrees of freedom for . In special cases, such as adsorbed large molecules, the rotational degrees of freedom can be limited