The control of shoulder disarticulation prostheses remains a challenging problem. Recently, a novel method, using targeted muscle reinnervation to develop additional myoelectric control sites, has Improved the control of myoelectric upper limb prosthesis In a patient with bilateral amputations at the shoulder disarticulation level . Encouraged by this achievement, we recorded high density surface electromyogram (EMG) signals from the patient's reinnervated muscles as he actuated a variety of different movements. We believe that the reinnervated muscle activation patterns revealed by the high density EMG recording have the potential to further improve the myoelectric prosthesis control. As the Initial stage of the study, this paper presents the experiment of high density surface EMG recording, the preliminary EMG data analysis and the framework for future investigation with advanced feature extraction and pattern recognition techniques.