IRCT2017070421383N7 IRCT 2017-09-26 Vice chancellor for research, Birjand University of Medical Sciences comparing the effect of trapezius squeezing test versus jaw thrust maneuver on the incidence of successful attempts for LMA insertion. comparison between the effect of using of trapezius squeezing test with jaw thrust maneuver on the incidence of successful attempts for LMA insertion. 2017-05-05 anticipated 138 Complete https://irct.ir/trial/18755 interventional Randomization: Randomized, Blinding: Triple blinded, Placebo: Not used, Assignment: Parallel, Purpose: Other, Other design features: The motor response recorded by an independent researcher who was not in the operating room while the test was performed. Also, the patients and the statistical researcher were uninformed about the study groups. For randomization we wrote numbers from 1 to 138 on separate papers and put it in envelops. Envelops were put in a box. At entrance to the operating room each patient picked up one envelope randomly from the box and gave it to the investigator who was responsible for doing maneuver. Squeezing the trapezius muscle for odd numbers and jaw thrust for even numbers was performed. N/A general anesthesia. Intervention 1: trapezius sqeezing test. Intervention 2: jaw thrust.