Participants are seeking to unleash the full therapeutic potential of a newly developed, customizable and potentially commericializable 10-channel Functional Electrical Stimulation (FES) to rehabilitate the gait of chronic stroke survivors. Each subject will undergo 18-sessions (\ 1 month) FES training. Participants will utilize the theory of muscle synergies from motor neurosciences, which are defined as neural modules of motor control that coordinate the spatiotemporal activation patterns of multiple muscles, to guide our personal selections of muscles for FES. It is hypothesized that chronic stroke survivors will learn from FES stimulations, over several daily sessions, both by suppressing the original abnormal muscle synergies and by employing the normal muscle synergies as specified in the FES. It is also expected that the walk synergies of the paretic side of chronic stroke survivors should be more similar to healthy muscle synergies at the two post-training time points than before training.