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A Journal on Applied Physiology, Biomechanics, Preventive Medicine,
Sports Medicine and Traumatology, Sports Psychology

Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,111

Frequency: Monthly

ISSN 0022-4707

Online ISSN 1827-1928


The Journal of Sports Medicine and Physical Fitness 2012 December;52(6):596-605



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

Brunetti O. 1, Botti F. M. 1, Roscini M. 1, Brunetti A. 2, Panichi R. 1, Filippi G. M. 3, Biscarini A. 4, Pettorossi V. E. 1

1 Section of Human Physiology, Department of Internal Medicine, University of Perugia, Perugia, Italy;
2 Department of Clinical Orthopedics and Traumatology, University of Perugia, Perugia, Italy;
3 Institute of Human Physiology, Sacro Cuore Catholic University, Rome, Italy;
4 Section of Medical Physic, Department of Surgical, Radiological and Odontostomatological Sciences, University of Perugia, Perugia, Italy

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, 100Hz, 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.

language: English


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