g., maximum load, cortical volume, or cortical bone density. Fluid particle movement could also underlie the decreased fluoroscopy labeling at the endocortical surface observed in this study. Similar to Warden et al. , we hypothesize that a synergistic effect of the mechanotransduction
pathway in combination with muscle stimulation is responsible for the observations KPT-8602 supplier made here. Higher muscle activity results in increased bone formation, but these effects could be lower in comparison to WBVV at frequencies of 5–10 Hz. Garman et al. , who also observed an increase in trabecular bone after whole-body vibration, demonstrated that bone cells can detect physical stimuli directly in the absence of significant bone deformation. In their study, the oscillatory motion resulted in increased trabecular bone without altering weight bearing characteristics. A limitation of this study was the use of only one frequency, one direction of vibration, and one amplitude. selleck compound The technique of WBVV used in this study was selected according to the results of Judex et al. , who demonstrated a significant increase of bone mass after WBV at 90 Hz compared to 45 Hz in rat tibiae. The results presented herein may not apply to subjects with older bones, nor may they apply to other bone regions, to males or even to humans. Our findings apply to a specific type of mechanical stimulus, and it is likely that other types
of vibration may result in varying effects on bone. Furthermore, rats were not fixed in a special position during vibration. In studies performed by Vershueren et al.  and Torvinen et al. , patients performed different actions during vibration. The test rats in this study moved freely on the vibration platform. It is possible that vibratory stimuli could change according to body posture. The effects could also potentially be dampened by the viscoelastic nature of the muscle–tendon apparatus . In contrast to other groups that had animals laying
down on the vibration platform, the rats in this study tended to run all over the cage, attempting to escape from the cage by standing on their hind feet and thereby receiving greater axial load. The presented data and data from other studies suggest that mechanical signals may have the potential to influence both bone and muscle. Considering the Adenosine SHP099 importance of muscle strength and function to the incidence of falls and fall-related injuries, whole-body vertical vibration may be useful in reducing the risk for osteoporosis-related fractures . Many questions remain regarding the benefit of whole-body vibration on the musculoskeletal system. It is not known, however, whether the effects will persist over time or whether such a treatment can help reduce falls and osteoporosis-associated fractures. Nevertheless, this non-drug method shows potential for the treatment of osteoporosis.