Four patients with adult acquired spastic hemiplegic hand disorders had brachioradialis to extensor digitorum communis tendon transfer to establish motor balance and improve prehensile hand function. All of the patients had volitional control of the wrist and finger flexors without control of the finger extensors, producing a dynamic hand deformity in which the patients could initiate grasp without release. Dynamic electromyography in these patients revealed electrical activity of the brachioradialis muscle during active elbow extension, making a seemingly "out-of-phase" muscle available for "in-phase" tendon transfer. At follow-up, ranging from 26 to 36 months (average of 30.2 months), all four patients improved three functional levels. Translated to functional capacity all of the patients had no functional capacity before operation and good assistive prehension afterward.