Tendon moment arm measurement using 3D MRI images

Using new three-dimensional (3D) methods, high resolution MRI images are used to measure tendon moment arm in the third MCP joint. Static images are acquired at multiple rotations of the joint. The 3D methods are: (1) a tendon excursion method that extends the method or Landsmeer and (2) a geometric method based upon the moment arm definition. Both methods should be more accurate than methods based upon 2D images. Repeating the imaging and analysis on a subject shows that the tendon excursion method is more repeatable than the geometric method.