title: Effect of vibration frequency on agonist and antagonist arm muscle activity.
abstract: OBJECTIVE
  This study aimed to assess the effect of vibration frequency (f out) on the electromyographic (EMG) activity of the biceps brachii (BB) and triceps brachii (TB) muscles when acting as agonist and antagonist during static exercises with different loads.
  
  
  METHODS
  Fourteen healthy men were asked to hold a vibratory bar as steadily as possible for 10 s during lying row (pulling) and bench press (pushing) exercise at f out of 0 (non-vibration condition), 18, 31 and 42 Hz with loads of 20, 50, and 80 % of the maximum sustainable load (MSL). The root mean square of the EMG activity (EMGRMS) of the BB and TB muscles was expressed as a function of the maximal EMGRMS for respective muscles to characterize agonist activation and antagonist coactivation.
  
  
  RESULTS
  We found that (1) agonist activation was greater during vibration (42 Hz) compared to non-vibration exercise for the TB but not for the BB muscle (p < 0.05); (2) antagonist activation was greater during vibration compared to non-vibration exercise for both BB (p < 0.01) and TB (p < 0.05) muscles; (3) the vibration-induced increase in antagonist coactivation was proportional to vibration f out in the range 18-42 Hz and (4) the vibration-induced increase in TB agonist activation and antagonist coactivation occurred at all loading conditions in the range 20-80 % MSL.
  
  
  CONCLUSIONS
  The use of high vibration frequencies within the range of 18-42 Hz can maximize TB agonist activation and antagonist activation of both BB and TB muscles during upper limb vibration exercise.
authors.affiliation: Sports Sciences Research Group, INEFC, Institut Nacional d'Educació Física de Catalunya, Centro de Barcelona, University of Barcelona, Avda. de l'Estadi s/n Anella Olímpica de Montjuïc, 08038, Barcelona, Spain, sergiorjbcn@gmail.com.
authors.forename: Sergio
authors.initials: S
authors.lastname: Rodríguez Jiménez
authors.forename: Adolfo
authors.initials: A
authors.lastname: Benítez
authors.forename: Miguel A
authors.initials: MA
authors.lastname: García González
authors.forename: Gerard
authors.initials: G
authors.lastname: Moras Feliu
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Maffiuletti
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology*; D014732:Vibration