title: Spectral electromyographic fatigue analysis of back muscles in healthy adult women compared with men.
abstract: OBJECTIVE
  To investigate the difference in back muscle endurance between normal adult women and men using surface electromyographic (EMG) power spectral analyses.
  
  
  METHODS
  Forty-five healthy subjects (22 men and 23 women) were studied during an unsupported trunk holding test for 120 seconds. Recording surface electrodes were placed over each erector spinae muscle at L1 level.
  
  
  METHODS
  Median frequency (MF), mean power frequency (MPF), and zero crossing rate (ZCR) were evaluated using the ME3000P Fast Fourier Transform spectrum analysis program. The rate of change was determined for each parameter during the test, and correlation was examined by Pearson's correlation.
  
  
  RESULTS
  The negative slopes of all indices of back muscle fatigue were significantly steeper in men than in women.
  
  
  CONCLUSIONS
  Our results indicated that the trunk holding test combined with EMG power spectral analysis of lumbosacral muscles is useful for the evaluation of fatigue performance of these muscles. Our results also showed a higher muscle endurance in healthy adult women than in men.
authors.affiliation: Department of Rehabilitation Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Umezu
authors.forename: T
authors.initials: T
authors.lastname: Kawazu
authors.forename: F
authors.initials: F
authors.lastname: Tajima
authors.forename: H
authors.initials: H
authors.lastname: Ogata
mesh_terms: D000328:Adult; D001415:Back / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012016:Reference Values; D012727:Sex Characteristics; D012815:Signal Processing, Computer-Assisted