Congenital Pseudarthrosis of the Clavicle: A Case Report and a Hypothesis for the Right-Side Predominance.

Congenital pseudarthrosis of the clavicle (CPC) is rare. It predominantly affects the right side for an unknown reason. Most of the reported cases are diagnosed outside the neonatal period.

On the rotational equations of motion in rigid body dynamics when using Euler parameters.

Many models of three-dimensional rigid body dynamics employ Euler parameters as rotational coordinates. Since the four Euler parameters are not independent, one has to consider the quaternion constraint in the equations of motion. This is usually done by the Lagrange multiplier technique.