Acute effects of transient vertical whole-body vibration

Abstract

The question as to whether shock-type whole-body vibration causes increasingly acute strain was investigated. Random vibrations were superimposed with shocks differing in amplitude and in number per unit of time in a systematic manner. The weighted root mean square (rms) acceleration was kept constant in all over the varied experiments. A total of 17 men were exposed to vibration from an electrohydraulic simulator. The following strain criteria were used: biodynamic behavior of the trunk and the head, electrical activity of the muscles of the back and the neck, subjective sensation, skin temperature in the lumbar area and visual and tracking performance. It was found that increasing shock amplitude and, in some experiments, also increasing numbers of shocks led to increasingly acute effects that varied, depending on the kind of shock used. New methods should be developed for the assessment of transient vibration that are better than the existing standards.

Whole-body vibration and occupational physical performance: a review

“…For a number of reasons, little can be interpreted from the results of these studies. Firstly, there was no change in thermal skin behaviour of lumbar and cervical muscles in the study by Dupuis et al (1991), despite testing high-amplitude vibration conditions. Conversely, the work by Spaul et al (1986) did demonstrate increases in rectal temperature and upper arm sweat rates (at most frequencies), albeit with only six male subjects.…”

“…Broadly, the studies examined either muscle activity or the reflex response of muscles. Regarding muscle activity, two studies found increased muscle activity during vibration (Santos et al 2008b;Seidel et al 1980) and three studies found no effect on muscular response during vibration (de Oliveira et al 2001;Dupuis et al 1991;Gant et al 2012). Three studies found an increase in the latency of the muscular response with vibration (Arora and Grenier 2013; Roll et al 1980;, and one study found no changes in reflex response (Santos et al 2008b).…”

“…One study examined rectal temperature and local sweat rate (Spaul et al 1986), whereas Dupuis et al (1991) investigated thermal behaviour of the skin. For a number of reasons, little can be interpreted from the results of these studies.…”

Seated human response to simple and complex impacts: Paraspinal muscle activity

“…In the past, occupational guidelines regulating human exposure to whole-body vibration such as ISO 2631ISO -1 (1997 were also applied to regulate exposure to shocks. However, after carefully examining epidemiological and laboratory evidence, Seidel et al (1986Seidel et al ( , 1997, Dupuis et al (1991), and Sandover (1997) pointed out that compared to sinusoidal vibration, exposure to vibrations containing shocks may be more hazardous to the health, particularly that of the spine. Hence, it is likely that these guidelines may not be effective measures to protect workers from shock-related low back injuries in certain workplaces (Wilder et al, 2002).…”

Whole-Body Shock and Vibration: Frequency and Amplitude Dependence of Comfort

“…The impact test data were used to determine linear mechanical response properties of a seated subject. Dupuis et al [8] tested subjects with a seat acceleration that consisted of mechanical shocks superposed on stationary random vibrations. Symmetric and asymmetric shock pro"les were used.…”