title: The interaction between body position and vibration frequency on acute response to whole body vibration.
abstract: OBJECTIVE
  The present study was designed to investigate the electromyographic (EMG) response in leg muscles to whole-body vibration while using different body positions and vibration frequencies.
  
  
  METHODS
  Twenty male sport sciences students voluntarily participated in this single-group, repeated-measures study in which EMG data from the vastus lateralis (VL) and the lateral gastrocnemius (LG) were collected over a total of 36 trials for each subject (4 static positions × 9 frequencies).
  
  
  RESULTS
  We found that vibration frequency, body position and the muscle stimulated had a significant effect (P-values ranged from 0.001 to 0.031) on the EMG response. Similarly, the muscle × frequency and position × muscle interactions were significant (P < 0.001). Interestingly, the frequency × positions interactions were not significant (P > 0.05).
  
  
  CONCLUSIONS
  Our results indicate that lower frequencies of vibration (25-35 Hz) result in maximal activation of LG, whereas higher frequencies (45-55 Hz) elicit the highest responses in the VL. In addition, the position P2 (half squat position with the heels raised) is beneficial both for VL and LG, independently of the vibration frequency.
authors.affiliation: Faculty of Sport Sciences, University of L'Aquila, Italy. digi.e@tiscali.it
authors.forename: Riccardo
authors.initials: R
authors.lastname: Di Giminiani
authors.forename: Francesco
authors.initials: F
authors.lastname: Masedu
authors.forename: Jozsef
authors.initials: J
authors.lastname: Tihanyi
authors.forename: Renato
authors.initials: R
authors.lastname: Scrimaglio
authors.forename: Marco
authors.initials: M
authors.lastname: Valenti
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D014732:Vibration; D055815:Young Adult