Vibration Exposure and Biodynamic Responses during Whole-Body Vibration Training

Wyle Laboratories, Inc., Houston, TX 77058, USA.
Medicine &amp Science in Sports &amp Exercise (Impact Factor: 3.98). 11/2007; 39(10):1794-800. DOI: 10.1249/mss.0b013e3181238a0f
Source: PubMed


Excessive, chronic whole-body vibration (WBV) has a number of negative side effects on the human body, including disorders of the skeletal, digestive, reproductive, visual, and vestibular systems. Whole-body vibration training (WBVT) is intentional exposure to WBV to increase leg muscle strength, bone mineral density, health-related quality of life, and decrease back pain. The purpose of this study was to quantitatively evaluate vibration exposure and biodynamic responses during typical WBVT regimens.
Healthy men and women (N = 16) were recruited to perform slow, unloaded squats during WBVT (30 Hz; 4 mm(p-p)), during which knee flexion angle (KA), mechanical impedance, head acceleration (Ha(rms)), and estimated vibration dose value (eVDV) were measured. WBVT was repeated using two forms of vibration: 1) vertical forces to both feet simultaneously (VV), and 2) upward forces to only one foot at a time (RV).
Mechanical impedance varied inversely with KA during RV (effect size, eta(p)(2): 0.668, P < 0.01) and VV (eta(p)(2): 0.533, P < 0.05). Ha(rms) varied with KA (eta(p)(2): 0.686, P < 0.01) and is greater during VV than during RV at all KA (P < 0.01). The effect of KA on Ha(rms) is different for RV and VV (eta(p)(2): 0.567, P < 0.05). The eVDV associated with typical RV and VV training regimens (30 Hz, 4 mm(p-p), 10 min.d(-1)) exceeds the recommended daily vibration exposure as defined by ISO 2631-1 (P < 0.01).
ISO standards indicate that 10 min.d(-1) WBVT is potentially harmful to the human body; the risk of adverse health effects may be lower during RV than VV and at half-squats rather than full-squats or upright stance. More research is needed to explore the long-term health hazards of WBVT.

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    • "Vibration induces physiological effects that are strongly influenced by parameters such as vibration frequency, amplitude , duration, and direction of exposure. Vibratory stimuli interact in a complex manner in the human body and cause physiological effects changing balance [1] [2] [3], cutaneous sensitivity [4], muscle activation [5], and blood flow [6], among others. In the ergonomic field, vibration is widely reported to produce motor disorders [7], loss of sensitivity, decreased blood flow, and pathologies such as vibration white finger or carpal tunnel syndrome [8]. "
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    ABSTRACT: The aim of this study was to investigate the effects 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. They spent 15 minutes on a vibration platform in the vertical mode at four different frequencies (31, 35, 40, and 44 Hz) with 1 mm of amplitude. All variables were measured before and after WBV exposure. Pressure sensation in five anatomical regions and both feet was determined using Von Frey monofilaments. Postural sway was measured using a force plate. Cutaneous temperature was obtained with an infrared camera. WBV influences the discharge of the skin touch-pressure receptors, decreasing sensitivity at all measured frequencies and foot regions (íµí±ƒ ≤ 0.05). Regarding balance, no differences were found after 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. The cutaneous temperature of the lower limbs decreased during and 10 minutes after WBV. WBV decreases touch-pressure sensitivity at all measured frequencies 10 min after exposure. This 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.
    Full-text · Article · Dec 2014 · The Scientific World Journal
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    • "Vibration has long been studied for its negative effects on the body, usually as the result of exposure in the workplace to either high intensity vibration or chronic exposure to large amounts of vibration over many years. These negative effects have been summarized in previous reviews and include damage to nerves, blood vessels, and joints (including the spine), as well as disruption of proprioception, vision, and hearing (Jordan et al., 2005; Lings and Leboeuf-Yde, 2000; Seidel, 1993; Abercromby et al., 2007). In spite of the existing negative reports, much research has been conducted regarding the potential beneficial effects of the WBV on the body. "
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    ABSTRACT: Whole body vibration (WBV) can be an important tool to treat patients with osteoarthritis (OA). The purpose of this study was to systematically review published research concerning the use of WBV in people with OA. In PubMed and Scopus, the number of publications (NP) is respectively to the keywords arthrosis, 289,586 and 10,569, osteoarthrosis, 299,158 and 3,952, arthritis, 251,453 and 236,849 and osteoarthritis, 56,323 and 80,008. Putting together the information found in the analyzed 4 papers, the numbers of subjects were ranging from 15 to 52 and frequencies ranging from 24 to 40 Hz. Self-report of the status of disease (WOMAC) was used in 2 papers, while the pain levels were evaluated by the visual analog scale (VAS) in 2 papers. Different tests were used in these studies, as (i) TUG, (ii) step test, (iii) 20-meter walk test, (iv) timed get up and go test (TGUG), (v) chair stand test (CST), (vi) 6-minute walk test (6MWT), (vii) knee muscle strength (extension/flexion) and (viii) proprioception (threshold for detection of passive movement (TDPM) to evaluate the effects promoted by the exercises due to the WBV. In conclusion, these studies indicate that the WBV could bring some benefits to patients with OA.
    Full-text · Article · Sep 2014
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    • "In addition, mechano-sensing during WBVT triggers reflex responses of the leg muscles that may become visible as synchronous or non-synchronous EMG activity [9], [23], [24], [26]–[28]. Narrow banded stop filters at the vibration frequency and its harmonics applied to a bipolar surface EMG record erase electrical motion artifacts [27], [29], [30] and H-wave like sum action potentials potentially occurring at the vibration frequency [28]. In this study, we did not apply band stop filters on the time domain of the EMG signal but excluded narrow frequency bands from the EMG spectra. "
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    ABSTRACT: In this study, we examined the acute effects of a 5-day daily whole-body vibration (WBV) training on electromyography (EMG) responses of the m. rectus femoris and m. gastrocnemius lateralis, heart rate (HR, continuously recorded), and blood lactate levels. The purpose of the study was to investigate the adaptation of muscle activity, heart rate and blood lactate levels during 5 days of daily training. Two groups of healthy male subjects performed either squat exercises with vibration at 20 Hz on a side alternating platform (SE+V, n = 20, age = 31.9±7.5 yrs., height = 178.8±6.2 cm, body mass = 79.2±11.4 kg) or squat exercises alone (SE, n = 21, age = 28.4±7.3 years, height = 178.9±7.4 cm, body mass = 77.2±9.7 kg). On training day 1, EMG amplitudes of the m. rectus femoris were significantly higher (P<0.05) during SE+V than during SE. However, this difference was no longer statistically significant on training days 3 and 5. The heart rate (HR) response was significantly higher (P<0.05) during SE+V than during SE on all training days, but showed a constant decline throughout the training days. On training day 1, blood lactate increased significantly more after SE+V than after SE (P<0.05). On the following training days, this difference became much smaller but remained significantly different. The specific physiological responses to WBV were largest on the initial training day and most of them declined during subsequent training days, showing a rapid neuromuscular and cardiovascular adaptation to the vibration stimulus.
    Full-text · Article · Jun 2014 · PLoS ONE
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