Postoperative Muscular Pain, ETOIMS (Electrical Twitch Obstructive Intramuscular Stimulation)

Inclusion Criteria: * Patients undergoing pancreatoduodenectomy in Gangnam Severance Hospital, Seoul, Korea * Patients who are able to perform daily activities before surgery and were able to walk independently. * Adults over 20 Exclusion Criteria: * Patients with history of previous open surgery * Patients who are not able to exercise due to severe musculoskeletal pain except surgery-related diseases * Patients who can not walk because of difficulty breathing related to myalgia * Patients who can not exercise due to severe musculoskeletal pain * Patients who had a limb defect before surgery and were unable to walk without assistive devices and others * Pregnant / lactating mothers * Patients who have cognitive impairment and can not answer the questionnaire * Patients with Pacemaker * Patients who can not read the consent form