title: Intra-abdominal pressure and activation of abdominal muscles in highly trained participants during sudden heavy trunk loadings.
abstract: METHODS
  Ten participants were exposed to heavy sudden trunk loads as they might occur during patient handling.
  
  
  OBJECTIVE
  The aim was to observe if well-trained men and women use their full rate of intra-abdominal pressure (IAP) development when exposed to heavy sudden trunk loads. Further, to elucidate to what degree the rectus abdominus muscle is activated when the IAP is developed.
  
  
  BACKGROUND
  Well-trained judo fighters are used to heavy sudden trunk loads and can produce a high IAP. It is unknown whether they use their full potential. IAP can increase the spinal stability and has been suggested to unload the spine. The unloading effect will, however, disappear if the development of the IAP demands substantial activity in the vertical fibers of the abdominal muscles.
  
  
  METHODS
  Five male and five female well-trained judo and jujitsu fighters were exposed to heavy sudden trunk loadings through imitated patient handling situations where the patient fell and the fighters should hold the patient and prevent the fall. IAP was measured with a catheter in the stomach. Along with the IAP measurement, EMG was measured on the abdominal muscles, and the load on the low back was quantified by a three-dimensional dynamic biomechanical calculation of the torques at the L4-L5 joint.
  
  
  RESULTS
  The well-trained judo fighters did not use their full potential of the IAP development when exposed to the heavy sudden trunk loads, but the women had to use a higher level of their IAP and extension torque capacity to comply with the heavy loads. The rectus abdominus muscle does not contribute to the IAP development when the trunk is exposed to a sudden heavy load.
authors.affiliation: National Institute of Occupational Health, Copenhagen, Denmark. me@ami.dk
authors.forename: Morten
authors.initials: M
authors.lastname: Essendrop
authors.forename: Bente
authors.initials: B
authors.lastname: Schibye
mesh_terms: D000009:Abdominal Muscles / Q000502:physiology*; D000058:Accidental Falls; D000062:Accidents, Occupational / Q000517:prevention & control; D000328:Adult; D019567:Back Injuries / Q000517:prevention & control; D004576:Electromyography; D005260:Female; D006281:Health Occupations; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D008365:Manometry; D016139:Martial Arts; D011312:Pressure; D017568:Rectus Abdominis / Q000502:physiology; D012727:Sex Characteristics; D013997:Time Factors; D019415:Torque; D014636:Valsalva Maneuver / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*