title: Stochastic resonance whole body vibration increases perceived muscle relaxation but not cardiovascular activation: A randomized controlled trial.
abstract: OBJECTIVE
  To investigate the acute effects of stochastic resonance whole body vibration (SR-WBV), including muscle relaxation and cardiovascular activation.
  
  
  METHODS
  Sixty-four healthy students participated. The participants were randomly assigned to sham SR-WBV training at a low intensity (1.5 Hz) or a verum SR-WBV training at a higher intensity (5 Hz). Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and self-reported muscle relaxation were assessed before and immediately after SR-WBV.
  
  
  RESULTS
  Two factorial analyses of variance (ANOVA) showed a significant interaction between pre-vspost-SR-WBV measurements and SR-WBV conditions for muscle relaxation in the neck and back [F(1,55) = 3.35,P= 0.048, η2= 0.07]. Muscle relaxation in the neck and back increased in verum SR-WBV, but not in sham SR-WBV. No significant changes between pre- and post-training levels of SBD, DBD and HR were observed either in sham or verum SR-WBV conditions. With verum SR-WBV, improved muscle relaxation was the most significant in participants who reported the experience of back, neck or shoulder pain more than once a month (P< 0.05).
  
  
  CONCLUSIONS
  A single session of SR-WBV increased muscle relaxation in young healthy individuals, while cardiovascular load was low. An increase in musculoskeletal relaxation in the neck and back is a potential mediator of pain reduction in preventive worksite SR-WBV trials.
authors.affiliation: Achim Elfering, Christian Burger, Department of Work and Organizational Psychology, University of Bern, 3000 Bern, Switzerland.
authors.forename: Achim
authors.initials: A
authors.lastname: Elfering
authors.affiliation: Achim Elfering, Christian Burger, Department of Work and Organizational Psychology, University of Bern, 3000 Bern, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Burger
authors.affiliation: Achim Elfering, Christian Burger, Department of Work and Organizational Psychology, University of Bern, 3000 Bern, Switzerland.
authors.forename: Volker
authors.initials: V
authors.lastname: Schade
authors.affiliation: Achim Elfering, Christian Burger, Department of Work and Organizational Psychology, University of Bern, 3000 Bern, Switzerland.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Radlinger
keywords: Blood pressure; Heart rate; Low back pain; Musculoskeletal system; Prevention