Neuroscience Letters 533 (2013) 81–85 Contents lists available at SciVerse ScienceDirect Neuroscience Letters jou rn al h om epage: www.elsevier.com/locate/neulet Human cutaneous sensors on the sole of the foot: Altered sensitivity and recovery time after whole body vibration Anelise Sonza a,b,∗ , Christian Maurer a , Matilde Achaval b , Milton A. Zaro b , Benno M. Nigg a a Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada b Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil h i g h l i g h t s ◮ Whole body vibration affects the discharges of fast-adapting skin mechanoreceptors. ◮ Recovery time provides a time window of how long the effects of WBV can last. ◮ Vibration induces a reduction in touch pressure and vibration sensitivity. ◮ No gender differences were found. a r t i c l e i n f o Article history: Received 11 September 2012 Received in revised form 9 November 2012 Accepted 14 November 2012 Keywords: Mechanoreceptors Post vibratory effects Whole body vibration Human tactile sensitivity Exercise a b s t r a c t The goal of this study was to investigate the effect of whole body vibration (WBV) on human tactile sensitivity, both the immediate effects and the recovery time in the case of altered sensitivity. Twenty adults (25.3 ± 2.6 years, 10 males) participated in a 10-min WBV session, at a frequency of 42 Hz with 2 mm amplitude in a spiral mode. Sensitivity was measured before and four times after WBV exposure. Pressure sensation was determined using Von Frey monofilaments. Vibration perception thresholds for 30 and 200 Hz were measured using a custom built neurothesiometer. The sensation was measured in 5 anatomical regions of the right foot. Sensitivity of measured cutaneous perception was significantly reduced. Fast-adapting mechanoreceptors for 200 Hz and 30 Hz showed 5.2 and 3.8 times lower sensation values immediately after WBV, respectively. Pressure sensation was 2 times lower in comparison to the baseline condition. In general, tactile sensitivity recovery time was between 2 and 3 h. WBV influences the discharge of fast-adapting skin mechanoreceptors. By determining the recovery time, it might be possible to estimate how long the effects of WBV on tactile sensitivity last. © 2012 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Whole body vibration (WBV) training platforms have been widely used for rehabilitation and/or performance purposes [19]. The reduced effort required to perform exercises in these machines, especially among patients with disabilities, might explain why this equipment has become so popular. It is important to investigate the responses to WBV in the human system in order to make safe recommendations for its use. Abbreviations: WBV, whole body vibration; SA, slow adapting mechanorecep- tors; FA, fast adapting mechanoreceptors; VPT, vibration perception threshold; TENS, transcutaneous electrical nerve stimulation. ∗ Corresponding author at: Instituto de Ciências Básicas da Saúde, UFRGS, Rua Sarmento Leite, 500, 90046-900 Porto Alegre, RS, Brazil. Tel.: +55 51 33083624; fax: +55 51 3308 3092. E-mail address: anelise.sonza@gmail.com (A. Sonza). In WBV, the skin is the first tissue that receives the vibra- tion stimulus. The feet have various receptors in the skin that provide feedback to the central nervous system [7,8,11]. The nervous conduction from the mechanoreceptors travels along large diameter afferent A  /A  sensory fibers. They are clas- sified as slow (SA) or fast (FA) adapting receptors. The SA receptors produce sustained responses to static stimulation. The FA receptors are sensitive to the rapid application and release of a stimulus [9] and are particularly sensitive to mechani- cal vibrations [17]. FA mechanoreceptors can be divided into Meissner and Pacinian corpuscles, the former are related to low (30 Hz) and the latter to high (200 Hz) vibration frequen- cies. WBV has been shown to influence large diameter fibers, with sensitivity being reduced immediately after its application, as shown by touch-pressure [16] and the vibration percep- tion (200 Hz) threshold (VPT) [20]. Notwithstanding, there are very few studies which report the effects of WBV on foot sensitivity. 0304-3940/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.neulet.2012.11.036