Abnormal intermuscular coordination in stroke-affected upper limbs contributes to motor deficits after stroke. In particular, abnormalities in the activation of upper limb muscle synergies after stroke were demonstrated for endpoint force control during isokinetic exercises. This study aimed to investigate the feasibility of isokinetic training to alter these abnormal synergy activations and improve motor control. Muscle synergies and Wolf Motor Function Test Functional Ability Scale (WMFT-FAS) score were compared before and after three weeks of electromyography-based training. The proposed training changed the synergy activation and improved the WMFT-FAS score in a chronic stroke survivor while preserving the muscle weights of the synergies.Clinical Relevance- This study presents the feasibility of neuromuscular training to modify the activation of upper limb muscle synergies against stroke-specific patterns of intermuscular coordination and improve WMFT-FAS score.