Back pain and Rescuer fatigue following CardioPulmonary Resuscitation by kneeling, standing on taboret, and standing postures

INTERVENTION: Cardiopulmonary resuscitation for 10 minutes by using kneeling, standing, and standing on taboret postures. Since this is a prospective and cross‐over trial, each of the participants should complete three different CPR posture within 3 weeks in one week apart. Therefore, each of the sequences of CPR should follow up for at least 48 hours, but the total follow‐up period for each of them will be 3 weeks and two days. CONDITION: Rescuer fatigue for resuscitation ; Signs and Symptoms ; Rescuer fatigue PRIMARY OUTCOME: 1. Severity of back pain (by Brief Pain Inventory Short Form), measured 24 hours and 48 hours post CPR; 2. Rescuer fatigue (effective compression of cardiac massage) ‐ detected by Laerdal Resusci‐Anne® Skillreporter™ mannequin, measured during 10 minutes of cardiac massage SECONDARY OUTCOME: Range of motion of elbow and back with different CPR postures (detected by flexible goniometer), measured during 10 minutes of cardiac massage. INCLUSION CRITERIA: Health care providers working at the Emergency Deparment that have: 1. Clinical work experience longer than 2 years 2. Experience of performing CPR for more than 20 times