Estimating joint centres using global optimisation and its effect on estimated joint kinetics

The calculation of three-dimensional joint kinematic and kinetic data in human gait requires an accurate representation of the underlying bony structure to define an anatomical joint centres, and axes of rotation. Traditional estimates involve placing markers over strategic bony landmarks, which are used to define joint centres and an anatomical coordinate system. However, these methods can be inaccurate, particularly when skin movement is greatest across bony landmarks. To overcome such issues, a global optimisation routine can be used to define joint centres, using constraints on the joint range of motion. Such an approach has been shown to improve kinematic accuracy compared to traditional techniques,
particularly in frontal and transverse planes. The purpose of this paper was to present differences in estimated joint kinetic
data comparing traditional methods with an optimisation approach.