title: Older Age Is Associated with Lower Optimal Vibration Frequency in Lower-Limb Muscles During Whole-Body Vibration.
abstract: OBJECTIVE
  The aim of this study was to compare the optimal vibration frequency (OVF), which corresponds to maximal electromyographic muscle response during whole-body vibration, between young, middle-aged, and older women in four muscles of the lower-limbs.
  
  
  METHODS
  OVF was measured as the frequency corresponding to maximal root mean square of the surface electromyogram (RMSmax) during a continuous incremental protocol, with a succession of vibration frequencies from 20 to 55 Hz (A = 2 mm), on the vastus lateralis, vastus medialis, rectus femoris, and gastrocnemius lateralis muscles of the dominant lower-limb. Seventy-eight women were divided into three age groups, that is, young, 21.6 ± 2.4 yrs; middle aged, 43.0 ± 5.2 yrs; and older, 74.2 ± 6.0 yrs.
  
  
  RESULTS
  OVF in the vastus medialis was lower in the older women than in the middle-aged and young women, whereas OVF in the vastus lateralis was lower in the older than in the young women. There were no differences in OVF between muscles within each group. RMSmax was higher in the older than in the young women in all muscles.
  
  
  CONCLUSIONS
  Age range should be taken into consideration when determining OVF because it decreases with age. Properly individualizing the vibration protocol might greatly influence neuromuscular effects of vibration training.
authors.affiliation: From the Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Rome (FC, GO, JH, LL, AM, FP, MS); and Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy (AG).
authors.forename: Flaminia
authors.initials: F
authors.lastname: Carlucci
authors.forename: Giorgio
authors.initials: G
authors.lastname: Orlando
authors.forename: Jonida
authors.initials: J
authors.lastname: Haxhi
authors.forename: Luca
authors.initials: L
authors.lastname: Laudani
authors.forename: Arrigo
authors.initials: A
authors.lastname: Giombini
authors.forename: Andrea
authors.initials: A
authors.lastname: Macaluso
authors.forename: Fabio
authors.initials: F
authors.lastname: Pigozzi
authors.forename: Massimo
authors.initials: M
authors.lastname: Sacchetti
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D015331:Cohort Studies; D004576:Electromyography / Q000379:methods; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D035002:Lower Extremity; D008875:Middle Aged; D015999:Multivariate Analysis; D009119:Muscle Contraction / Q000502:physiology*; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000502:physiology*; D018570:Risk Assessment; D016896:Treatment Outcome; D014732:Vibration / Q000627:therapeutic use*; D055815:Young Adult