Anatomically accurate model of EMG during index finger flexion and abduction derived from diffusion tensor imaging
Fig 1
3D models derived from MRI/DWI data with reference cadaveric specimen.
(a) Isosurface rendering of the MRI data with fiber tracks of the superficial (red) and deep (pink) heads of the FDI muscle at rest (the positions of the first and second metacarpals are highlighted). Elliptical objects around the subject’s hand are oil capsules utilized as geometrical reference. (b) Closer view of muscle fiber tracks of both heads of the FDI. (c) Superficial and deep heads of the FDI muscle in a cadaveric specimen. Note consistency in fiber direction, origin, and insertion in both superficial and deep heads of the muscle in the DTI derived image and the cadaveric specimen. (d) Segmented hand model derived from MRI data. (e) Finite element discretization of the hand model (tetrahedral mesh). EMG electrodes used in simulations and experimental recordings are indicated by the red discs. (f) The FDI muscle (beige) is presented with the muscle fiber tracks derived from the DTI analysis (red and pink) and the vector field (blue) generated from the interpolation/extrapolation of these tracks directions over the entire FDI volume. This vector field determines the direction of highest electrical conductivity and the trajectories of virtual muscle fibers within the FDI.