title: Electromyography activity of selected trunk muscles during cardiopulmonary resuscitation.
abstract: BACKGROUND
  Understanding trunk muscle activity during chest compression may improve cardiopulmonary resuscitation (CPR) training strategies of CPR or prevent low back pain. This study investigates the trunk muscle activity pattern of chest compression in health care providers to determine the pattern alternation during chest compression.
  
  
  METHODS
  Thirty-one experienced health care providers performed CPR for 5 minutes at a frequency of 100 compressions per minute. An electromyography (EMG) system was used to record muscle activity in the first minute, the third minute, and the fifth minute. Electrodes were placed bilaterally over the pectoralis major, latissimus dorsi, rectus abdominis, erector spinae, and gluteus maximus. We calculated the root mean square (RMS) value and maximal amplitude of the EMG activity, median frequency, and delivered force.
  
  
  RESULTS
  The maximal amplitude of EMG of the pectoralis major, erector spinae, and rectus abdominis showed large muscle activity above 45% of maximal voluntary contraction under chest compression. There were no significant differences in the RMS value of one chest compression cycle (RMS100%) and median frequency for all muscles at the first, third, and fifth minutes. Only gluteus maximus showed significant imbalance. The EMG ratios (erector spinae/rectus abdominis; erector spinae/gluteus maximus) increased significantly over time. The delivered force, compression depth, and number of correct depth decreased significantly over time.
  
  
  CONCLUSIONS
  We suggest that the muscle power training for the pectoralis major, erector spinae, and rectus abdominis could be helpful for health care providers. Keeping muscle activity balance of bilateral gluteus maximus and maintaining the same level of EMG ratios might be the keys to prevent low back pain while performing CPR.
authors.affiliation: Department of Physical Therapy, Fooyin University, Kaohsiung, Taiwan.
authors.forename: Jui-Yi
authors.initials: JY
authors.lastname: Tsou
authors.affiliation: Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan; Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan. Electronic address: fcsu@mail.ncku.edu.tw.
authors.forename: Fong-Chin
authors.initials: FC
authors.lastname: Su
authors.affiliation: Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Pai-Chin
authors.initials: PC
authors.lastname: Tsao
authors.affiliation: Department of Emergency Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Ming-Yuan
authors.initials: MY
authors.lastname: Hong
authors.affiliation: Department of Physical Therapy, Fooyin University, Kaohsiung, Taiwan.
authors.forename: Su-Chun
authors.initials: SC
authors.lastname: Cheng
authors.affiliation: Department of Physical Therapy, Fooyin University, Kaohsiung, Taiwan.
authors.forename: Hsun-Wen
authors.initials: HW
authors.lastname: Chang
authors.affiliation: Department of Physical Therapy, Fooyin University, Kaohsiung, Taiwan.
authors.forename: Jin-Shiou
authors.initials: JS
authors.lastname: Yang
authors.affiliation: Department of Emergency Medicine, National Cheng Kung University, Tainan, Taiwan. Electronic address: chich@mail.ncku.edu.tw.
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Chi
mesh_terms: D000328:Adult; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects* / Q000379:methods; D004576:Electromyography; D005260:Female; D006336:Heart Massage / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D017116:Low Back Pain / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010369:Pectoralis Muscles / Q000502:physiology; D017568:Rectus Abdominis / Q000502:physiology; D064171:Superficial Back Muscles / Q000502:physiology; D013909:Thorax