Inclusion Criteria:  signed informed written consent BMI 17.5-30 kg/m^2 ASA <= 3 supine positioning during surgery with intraoperative access to both arms absence of allergy to muscle relaxants and reversal agents absence of neuromuscular disease  Exclusion Criteria:  ambulatory patients for whom discharge is planned within 12 hours of anaesthesia patients undergoing minor surgical procedures scheduled outside the operating room patients who are endotracheally intubated prior to surgery pregnancy indication for rapid sequence induction patients undergoing arm surgery patients with preceding injuries impairing muscle or nerve function of the arm (e.g., finger amputation)