Electrical stimulation of skeletal muscles is widely used in rehabilitation with the purpose of preserving or recovering muscle mass, improving muscle function and restoring purposeful movement after CNS damage. Electrically-induced muscle contractions can be obtained by delivering electrical pulses over a peripheral nerve trunk (nStim) or to the terminal nerve branches at the muscle level (mStim). In the last years, several types of stimulation have been developed to achieve a more “physiological” contraction that leads to fatigue reduction. This study wants to focus on architectural changes of Tibialis Anterior (TA), with regard to the fact that stimulation over the muscle (mStim) or the nerve (nStim) activate different portions of muscle.