Left hemiplegia is paralysis of the left side of the body due to brain stroke. In brain stroke, brain cells die due to oxygen starvation. If this happens in the right side of the brain then the left side becomes dysfunctional. But since the left side brain is unaffected, the right side of body remains fully functional. Generally, neuro muscular stimulation using surface electrodes placed at the nerve points simulates as if current is coming from the brain and corresponding functional movement will occur. Now physical exercise/physiotherapy is very important for motor recovery. But since the brain is not sending (or incapable of)any signal to initiate the movement, either one has to use active side force movement in inactive side. Now since the active side is functioning normally -- i.e. brain is sending correct signals -- we can tap into these signals and apply to the inactive side to induce movement. This signal might require amplifications...left side muscles being weak might require stronger signal current to get movement. It's a noninvasive technique to help stroke survivors to use the non-affected side for physiotherapy, rehabilitation.