Background: The purpose of this study is to find how trunk muscles mainly used in cardio-pulmonary resuscitation, including pectoralis major, rectus abdominis, and erector spinae, influence the result of 8-minute when the muscles have six-weeks plank exercise, and to analyze the duration time of exercise effect. Methods: Study subjects were 30 participants taking a relevant course for 24 months. After they had plank exercise for six weeks, they didn't have any exercises including plank exercise for six weeks. As such, the students participated in the 12-weeks program. For chest compression simulation, a practictical mannequin was used. Without any respiration, a single rescuer continued to perform only chest compression for 8 minutes. Results: Regarding their change in a muscle mass by plank exercise, there was a statistically significant difference in the change from 4th to 8th week after the program (p<.01). The muscle activity change had a statistically significant difference from 3rd to 10th week (p<.01). The chest compression depth had a statistically significant difference from 4th to 8th week (p<.01). The chest compression rate didn't had a statistically significant difference for 12 weeks. In addition, insufficient chest relaxation height after compression had a statistically significant difference from 4th to 10th week(p<.01). The chest compression maintenance time had a statistically significant difference from 2nd to 12th week (p<.01). Conclusion: If the study subjects have three sets of plank exercise program for five weeks, which consisted of one set of 10 times of 30-second motion and 20-second rest and does not have up to two weeks of detraining, the plank exercise is considered to be helpful for them in out of hospital cardiac arrest at the time when there is no use of mechanical chest compression device.Trial registration: The study was registered on 12/15/2015 in the Chungnam National University Hospital with number 2015-10-035-005.

Purpose:The goal of this study was to characterize the difficulty index of the items in the skills test components of the class I and II Korean emergency medical technician licensing examination (KEMTLE), which requires examinees to select items randomly.Methods:The results of 1,309 class I KEMTLE examinations and 1,801 class II KEMTLE examinations in 2013 were subjected to analysis. Items from the basic and advanced skills test sections of the KEMTLE were compared to determine whether some were significantly more difficult than others.Results:In the class I KEMTLE, all 4 of the items on the basic skills test showed significant variation in difficulty index (P<0.01), as well as 4 of the 5 items on the advanced skills test (P<0.05). In the class II KEMTLE, 4 of the 5 items on the basic skills test showed significantly different difficulty index (P<0.01), as well as all 3 of the advanced skills test items (P<0.01).Conclusion:In the skills test components of the class I and II KEMTLE, the procedure in which examinees randomly select questions should be revised to require examinees to respond to a set of fixed items in order to improve the reliability of the national licensing examination.