Muscles Used for Chest Compression Under Static and Transportation Conditions

Abstract

Background. Unstable conditions during ambulance transportation are not conducive to the performance of high-quality cardiopulmonary resuscitation by emergency medical technicians. Objective. The present study was conducted to clarify differences in the quality of chest compression and associated muscle activity between static and ambulance transportation conditions. Methods. Nine paramedic students performed chest compression for 5 minutes on the floor and during ambulance transportation. Compression rate and depth and success and error rates of chest compression were determined using the Resusci Anne manikin with a PC SkillReporting System (Laerdal Medical). Integrated electromyography (i-EMG) values of eight different muscles were also recorded bilaterally during the first and last 30 seconds of compression. Results. There was no significant difference in compression rate per minute (p = 0.232) and depth of chest compression (p = 0.174) between the two conditions. The success rate was significantly lower under the ambulance transportation condition than under the static condition (p = 0.0161). Compared with those under the static condition, the total i-EMG values were significantly lower for the multifidus (p = 0.0072) and biceps femoris (p < 0.0001) muscles and significantly higher for the deltoid (p = 0.0032), pectoralis major (p = 0.0037), triceps brachii (p = 0.0014), vastus lateralis (p < 0.0001), and gastrocnemius (p = 0.0004) muscles under the ambulance transportation condition. Conclusions. Chest compression is performed mainly through flexion and extension of the hip joint while kneeling on the floor and through the elbow and shoulder joints while standing in a moving ambulance. Therefore, the low quality of chest compression during ambulance transportation may be attributable to an altered technique of performing the procedure.