Research Article Whole Body Vibration at Different Exposure Frequencies: Infrared Thermography and Physiological Effects Anelise Sonza, 1,2 Caroline C. Robinson, 2 Matilde Achaval, 1,3 and Milton A. Zaro 1 1 Programa de P´ os-Graduac ¸˜ ao em Neurociˆ encias, Instituto de Ciˆ encias B´ asicas da Sa´ ude, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, 90050-170 Porto Alegre, RS, Brazil 2 Programa de P´ os-Graduac ¸˜ ao em Ciˆ encias da Sa´ ude, Universidade Federal de Ciˆ encias da Sa´ ude de Porto Alegre, Sarmento Leite, 245, 90050-170 Porto Alegre, RS, Brazil 3 Departamento de Ciˆ encias Morfol´ ogicas, Instituto de Ciˆ encias B´ asicas da Sa´ ude, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, 90050-170 Porto Alegre, RS, Brazil Correspondence should be addressed to Anelise Sonza; anelise.sonza@gmail.com Received 24 July 2014; Revised 12 December 2014; Accepted 15 December 2014 Academic Editor: Yasumasa Yoshiyama Copyright © 2015 Anelise Sonza et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. he aim of this study was to investigate the efects of whole body vibration (WBV) on physiological parameters, cutaneous temperature, tactile sensitivity, and balance. Twenty-four healthy adults (25.3 ± 2.6 years) participated in four WBV sessions. hey spent 15 minutes on a vibration platform in the vertical mode at four diferent frequencies (31, 35, 40, and 44 Hz) with 1 mm of amplitude. All variables were measured before and ater WBV exposure. Pressure sensation in ive anatomical regions and both feet was determined using Von Frey monoilaments. Postural sway was measured using a force plate. Cutaneous temperature was obtained with an infrared camera. WBV inluences the discharge of the skin touch-pressure receptors, decreasing sensitivity at all measured frequencies and foot regions ( ≤ 0.05). Regarding balance, no diferences were found ater 20 minutes of WBV at frequencies of 31 and 35 Hz. At 40 and 44 Hz, participants showed higher anterior-posterior center of pressure (COP) velocity and length. he cutaneous temperature of the lower limbs decreased during and 10 minutes ater WBV. WBV decreases touch-pressure sensitivity at all measured frequencies 10 min ater exposure. his may be related to the impaired balance at higher frequencies since these variables have a role in maintaining postural stability. Vasoconstriction might explain the decreased lower limb temperature. 1. Introduction Vibration induces physiological efects that are strongly inluenced by parameters such as vibration frequency, ampli- tude, duration, and direction of exposure. Vibratory stimuli interact in a complex manner in the human body and cause physiological efects changing balance [1–3], cutaneous sensitivity [4], muscle activation [5], and blood low [6], among others. In the ergonomic ield, vibration is widely reported to produce motor disorders [7], loss of sensitivity, decreased blood low, and pathologies such as vibration white inger or carpal tunnel syndrome [8]. Whole body vibration (WBV) training platforms have been considered an exercise modality and the reduced efort required with their use might explain their popularity [9, 10]. he variety of WBV platform settings (vibration mode, frequency, amplitude, and exposure duration) that have been used in the available studies and the controversial indings may, in part, explain the inexistence of training standards [10– 13]. An understanding of its acute efects and studies with a wider range of platform settings might help elucidate this question. A better understanding of the parameter settings might also help health area professionals to choose the most suitable settings for speciic rehabilitation conditions, sports training, and normal subjects. he skin is the body’s largest organ. he dermis comprises a dense network of mechanoreceptors, in addition to nerve endings that penetrate the epidermis and together provide the senses of touch, pressure, vibration, pain, and heat. It works as the body’s thermoregulator, controlling blood low within a few millimeters of the body surface and aids the sense of balance to modulate posture and gait. Hindawi Publishing Corporation e Scientific World Journal Volume 2015, Article ID 452657, 10 pages http://dx.doi.org/10.1155/2015/452657