In numerical simulations of skeletal muscle contractions, geometric
information is of major importance. The
aim of the present study was to determine whether the diffusion tensor
imaging (DTI) technique is suitable
to obtain valid input with regard to skeletal muscle fibre direction. The
accuracy of the DTI method was
therefore studied by comparison of DTI fibre directions in the rat tibialis
anterior muscle with fascicle
striation patterns visible on high-resolution magnetic resonance imaging
(MRI) and with fibre directions in
an actual longitudinal section (ALS) through the same muscle. The results
showed an excellent qualitative
agreement between high-resolution MRI and DTI. Despite less accurate quantitative
comparison with ALS,
it was concluded that DTI does indeed measure skeletal muscle fibre direction.
After the experiment, it was
possible to determine an appropriate voxel size (0.9 mm3) that
provided enough resolution and acceptable
accuracy (5°) to use DTI fibre directions in biomechanical analyses.
Muscle deformation during contraction,
resulting from a finite element simulation with a mesh that was directly
generated from the experimental
data, has been presented.