Focal vibration of quadriceps muscle enhances leg power and decreases knee joint laxity in female volleyball players

J Sports Med Phys Fitness. 2012 Dec;52(6):596-605.


Aim: This double-blind randomized controlled study aims at determining the effect of repeated muscle vibration (rMV) on explosive and reactive leg power and on knee laxity of female volleyball players.

Methods: Eighteen voluntary volleyball athletes, belonging to the same senior regional level team (age=22.7 ± 3 years, height=180.3 ± 5 cm, mass= 64 ± 4 kg) were assigned to three groups (N.=6) for vibration on contracted quadriceps (VC), vibration on relaxed muscle (VR), and sham vibration (NV), respectively. Intervention consisted in 3 rMV sessions performed in 3 consecutive days. In each session, 100 Hz, 300-500 μm amplitude vibratory stimuli were bilaterally delivered to the quadriceps in three consecutive 10-minutes applications. Explosive and reactive leg power and knee joint laxity were evaluated 1 day before, and 1, 30, and 240 days after intervention.

Results: In VC group, explosive and reactive leg power increased respectively by ~16% and ~9% at 1 day, by ~19% and ~11% at 30 days and by ~26% and ~13% at 240 days, concomitantly knee laxity decreased by ~6%, ~15% and ~18% at the same times. These changes were significantly larger than in the other groups, in which leg power increment and knee joint laxity reduction remained close to ~3%, ~5% and ~10% at 1, 30 and 240 days, respectively.

Conclusion: Combined bilateral voluntary contraction and rMV of the quadriceps muscles is a short-lasting, non-invasive technique that can significantly and persistently improve muscle performance and knee laxity in volleyball women players.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Joint Instability / physiopathology
  • Joint Instability / prevention & control*
  • Knee Joint / physiopathology*
  • Leg / physiology*
  • Physical Therapy Modalities*
  • Quadriceps Muscle / physiology*
  • Vibration
  • Volleyball / physiology*
  • Young Adult