Background: We designed a new 1-handed chest compression method, the "elbow-lock" chest compression (ELCC), for a single rescuer in pediatric cardiopulmonary resuscitation (CPR). Then, we compared the effectiveness between the ELCC and standard chest compression (SCC) method.Methods: This prospective, randomized controlled, crossover simulation trial studied 34 emergency medical professionals, including physicians, nurses, and EMTs. We compare the quality of chest compression and fatigue point time between the ELCC and the SCC.Results: Participants who performed the ELCC method maintained a proper depth of compression compared with SCC method (50.0 ± 0.3 mm vs 40.5 ± 0.4 mm, P < 0.001). However, the 2 methods did not differ in terms of compression velocity since neither reached the standard velocity (96.7 ± 7.1/minutes vs 91.7 ± 7.0/minutes, P < 0.016). With respect to the overall score, ELCC was more effective than the SCC (91.6 ± 3.7% vs 85.3 ± 8.8%, P = 0.002). In addition, the fatigue point time was slower in the ELCC group than the SCC group (7.3 ± 0.3/minutes vs 6.1 ± 0.4/minutes, P < 0.001). Conclusions:The single rescuer ELCC method is an effective alternative to the SCC method for pediatric CPR because the ELCC method can prevent elbow flexion.Trial registration: Our research is simulation manikin study. So we do not need to "trial registration"