Finger joint kinematics from MR images

Accurate and quantitative analysis of human hand motion requires an understanding of the kinematics of the proximal and distal interphalangeal joints in three dimensions. This paper presents a technique to investigate in-vivo finger joint kinematics using magnetic resonance (MR) imaging. Bone surface models were extracted from MR images of the right hand of ten healthy subjects in four different postures. The relative motion of adjacent bones for all subjects was calculated and expressed as the helical axis and the angles around the axes of local bone coordinate system. The motion data indicated the change of axis orientation with flexion. After carefully selecting the subject and a pose with an appropriate flexional angle, studies determined that the mean inclination between the axes of the proximal and distal interphalangeal joints was approximately 14 [deg].