Long-term Effects of Mechanical Vibration Stimulus on the Bone Formation of Wistar Rats: An Assessment Method Based on X-rays Images.

BACKGROUND: Bone is a complex living tissue that adapts itself to the demands of mechanical stimuli such as physical activity and exercise. Whole-body vibration (WBV) is a type of exercise characterized by the transmission of mechanical vibration stimuli produced by a vibrating platform. This study aimed to investigated, in experimental model, the effect of WBV exercise on the bone in different frequencies through X-ray analysis. MATERIALS AND METHODS: Wistar rats were divided in three groups: control, exposed to WBV of 10 Hz and exposed to WBV of 20 Hz, during 8-weeks. All procedures to obtain the radiographic images were carried out before and after the experiments. The femur linear size and bone density measurements through radiographic images were performed in all animals. A factor of increase for bone density (FIBD) was determined. RESULTS: No differences were observed in the qualitative comparison between the groups, as well as radiographic bone density before the experiment. However, after the experiment the bone density increased in the rats exposed to WBV of 10 Hz and 20 Hz compared to control group. Also, the FIBD was higher in the groups exposed to WBV in comparison with control. CONCLUSION: These findings indicate an increase of the bone density dependent of the vibration stimulus frequency. In addition, this increase suggests a possible osteogenic effect to the mechanical vibrations of 10 and 20 Hz.

WHOLE-BODY VIBRATION EXERCISE IS WELL TOLERATED IN PATIENTS WITH DUCHENNE MUSCULAR DYSTROPHY: A SYSTEMATIC REVIEW.

BACKGROUND: Duchenne muscular dystrophy (DMD) is caused by a defective gene located on the X-chromosome, responsible for the production of the dystrophin protein. Complications in the musculoskeletal system have been previously described in DMD patients. Whole body vibration exercise (WBVE) is a treatment that improves musculoskeletal function in movement disorders. The aim of this study was to review the effects of WBVE on functional mobility, bone and muscle in DMD patients. MATERIALS AND METHODS: Four databases were searched. Three eligible studies were found; all three conclude the management of DMD patients with WBV was clinically well tolerated. The studies used a side-alternating WBV system, frequencies 7 - 24 Hz; and amplitudes 2 - 4 mm. RESULTS: A work indicates that a temporary increase in creatine kinase in DMD during the first days of WBV was observed, but other authors did not find changes. No significant changes in bone mass, muscle strength or bone markers. Some patients reported subjective functional improvement during training. Interpretation. CONCLUSION: It is concluded that WBV seems to be a feasible and well tolerated exercise modality in DMD patients.

Could whole body vibration exercises influence the risk factors for fractures in women with osteoporosis?

OBJECTIVE: The aim of this study was to review the literature about the relevance of the whole body vibration (WBV) in decreasing the number of fractures in osteoporotic women. METHODS: Searches were performed by three independent researchers through the PubMed and PEDro databases. RESULTS: Only 0.1% of the publications with "Fracture and osteoporosis" have a relation with WBV exercise. The achievements have revealed a positive effect of this exercise in patients with risk factors for fractures like osteoporosis. Protocols were performed two to three times a week, from 6 up to 18 months, and with 12.6 up to 40 Hz as frequencies. Different tools were used to evaluate the effects of the WBV exercise in conditions that could cause fractures in postmenopausal women. CONCLUSIONS: Although the paucity of research regarding direct effects of WBV in decreasing fractures, WBV could be a feasible and effective way to modify well-recognized risk factors for falls and fractures, improvements in some aspects of neuromuscular function and balance. More studies have to be performed establish protocols with well controlled parameters.