Effect of vibration on skin blood flow in an in vivo microcirculatory model

The effect of vibration on skin microcirculation was studied to investigate the possibility of clinical use of vibration to prevent and treat pressure ulcers. Vibrations at a vibrational intensity of 600, 800, or 1,000 mVpp with a fixed frequency of 47 Hz were applied horizontally to the ear of male hairless mice (n = 6 for each group) under inhalation anesthesia. The control group (n = 6) received no vibrations. Venular blood flow was measured by an intravital videomicroscope at the baseline and at 0, 5, and 15 min after the application of vibrations. A significant increase was observed in the 600 mVpp group 5 and 15 min after vibration in comparison to the control group (P = 0.002 and P = 0.046, respectively). We also detected increased blood flow in the 800 mVpp group (P = 0.028) and the 1,000 mVpp group (P = 0.012) 5 min after vibration; however, these increases attenuated after 15 min. These results indicate that direct skin vibration at a frequency of 47 Hz improves skin blood flow. The present study gives further support to the role of vibration on a short-term increase in skin blood flow.