Objective: To determine whether joint position affects muscle proton diffusion, fractional anisotropy and primary (lambda(1)), secondary (lambda(2)), and tertiary (lambda(3)) eigenvalues of calf muscles were compared among ankle positions of plantar flexion, intermediate, and dorsiflexion.
Conclusion: In tibialis anterior, fractional anisotropy and lambda(1) decreased, but lambda(2) and lambda(3) increased (p < 0.01) as the joint angle increased. Opposite results were obtained for the gastrocnemius and soleus (p < 0.05). These results indicate that joint position affects muscle proton diffusion.