title: Electromyographic activity of back muscles during stochastic whole body vibration.
abstract: OBJECTIVE
  Stochastic resonance whole body vibrations (SR-WBV) may reduce and prevent musculoskeletal problems (MSP). The aim of this study was to evaluate how activities of the lumbar erector spinae (ES) and of the ascending and descending trapezius (TA, TD) change in upright standing position during SR-WBV.
  
  
  METHODS
  Nineteen female subjects completed 12 series of 10 seconds of SR-WBV at six different frequencies (2, 4, 6, 8, 10, 12Hz) and two types of "noise"-applications. An assessment at rest had been executed beforehand. Muscle activities were measured with EMG and normalized to the maximum voluntary contraction (MVC%). For statistical testing a three-factorial analysis of variation (ANOVA) was applied.
  
  
  RESULTS
  The maximum activity of the respective muscles was 14.5 MVC% for the ES, 4.6 MVC% for the TA (12Hz with "noise" both), and 7.4 MVC% for the TD (10Hz without "noise"). Furthermore, all muscles varied significantly at 6Hz and above (p⋜0.047) compared to the situation at rest. No significant differences were found at SR-WBV with or without "noise".
  
  
  CONCLUSIONS
  In general, muscle activity during SR-WBV is reasonably low and comparable to core strength stability exercises, sensorimotor training and "abdominal hollowing" in water. SR-WBV may be a therapeutic option for the relief of MSP.
authors.affiliation: Department of Health, Bern University of Applied Sciences, Bern, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Blasimann
authors.forename: U
authors.initials: U
authors.lastname: Fleuti
authors.forename: M
authors.initials: M
authors.lastname: Rufener
authors.forename: A
authors.initials: A
authors.lastname: Elfering
authors.forename: L
authors.initials: L
authors.lastname: Radlinger
mesh_terms: D000293:Adolescent; D000328:Adult; D064131:Back Muscles / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology; D010865:Pilot Projects; D012146:Rest / Q000502:physiology; D013269:Stochastic Processes; D014732:Vibration; D055815:Young Adult