Muscle synergies are a widely recognized model of how the central nervous system overcomes the redundancy of the musculoskeletal system. Usually they are studied from surface EMG sampling one EMG signal from each muscle involved in the considered movement. However, specific studies showed that separated regions of some lower limb muscles (rectus femoris and vastus medialis for instance) may be excited independently. If, during a given motor task, different regions of the same muscle are elicited at different instants, it is then possible that a single muscle participates in different synergies. In this study, the main focus is extracting muscle synergies considering different regions of selected lower-limb muscles as totally distinct actuators.