The effect of multidirectional mechanical vibration on peripheral circulation of humans

Authors


  • 1

    Although, the vibratory device used by Zhang et al. (2003) also delivered <20% of its accelerative power in a direction perpendicular to the vibration axis.

  • 2

    The placebo devices were modified vibratory devices with which the generating motor had been detached from the vibratory plate. Hence whilst in operation, the placebo units looked and sounded like the vibratory units. However, it should be acknowledged that it was not possible to dampen vibration completely from the placebo units, and a small residual pulse was possible.

  • 3

    As participants were sat upright throughout testing, the occluded limb was below heart level. To compensate for the increased perfusion pressure associated with this position, an increased occlusion pressure of 140 mmHg rather than the standard 60 mmHg was necessary.

C. Button, Human Performance Centre, School of Physical Education, University of Otago, Dunedin, New Zealand
E-mail: chris.button@otago.ac.nz;
html: http://www.hpc.otago.ac.nz

Summary

The physiological response of humans to vibration has intrigued researchers for some time, and recently in relation to its potential as a non-pharmacological means to improve peripheral blood flow. A new vibration device [Arapal Technologies Ltd (ATL), Christchurch, New Zealand] for pain relief that purportedly delivers multidirectional vibration waveforms, has been developed. The aim of the study was to quantify the effect of 30 min of mechanical vibration (60 Hz) using two ATL massage devices concurrently upon local peripheral blood flow in healthy humans. On the basis of past work it was expected that acute exposure of the body to the vibratory stimulus would increase local peripheral blood flow. In a randomized cross-over design, mean blood flow (MBF) to the calf was measured using venous occlusion plethysmography before, during 3 min and after 30 min exposure to the vibratory devices or placebo (non-vibratory) devices. Statistical analysis revealed no consistent differences between conditions and considerable individual variability. The MBF increase tended to be higher in the vibration condition than the placebo condition (P = 0·16, 95% likely range = −14·4% to 82·2%), the mean increase from resting blood flow at the post-test was 26 ± 49% in the vibration condition and 12 ± 39% in the placebo condition. It took approximately 22 min of exposure to the vibratory stimulus to elicit peak blood flow (18 min with the placebo). Improvements in local blood flow may be beneficial in the therapeutic alleviation of pain or other symptoms resulting from acute or chronic musculoskeletal injuries.

Ancillary