Seated body apparent mass response to vertical whole body vibration: Gender and anthropometric effects

Effects of elastic seats on seated body apparent mass responses to vertical whole body vibration

“…The use of a vertical back support, however, yields minimal effect on the frequency corresponding to the primary peak for the PUF seat. This trend is also evident for the rigid seat and has been widely reported in many studies (Wang, Rakheja, and Boileau 2004;Nawayseh and Griffin 2005;Hinz et al 2006;Patra et al 2008;Toward and Griffin 2011;Dewangan et al 2013b). The frequency corresponding to the mean peak AM for seat C, however, tends to be considerably lower with the back support compared with that without the back support.…”

“…The scatter in the AM magnitudes in the lower frequency range can thus be primarily attributed to variations in the subjects' body mass (52 to 106 kg). Previous studies on rigid and elastic seats have also reported large variability in the AM magnitude at lower frequencies (Wang, Rakheja, and Boileau 2004;Nawayseh and Griffin 2005;Hinz et al 2006;Patra et al 2008;Toward and Griffin 2011;Dewangan et al 2013aDewangan et al , 2013b. The results in this study show that the primary magnitude peaks occur within narrow frequency bands (3.94 to 5.25, 3.94 to 5.13 and 3.81 to 5.63 Hz ranges for seats A, B and C, respectively, for the NB support condition).…”

“…Despite the differences, both the studies observed lower peak AM magnitudes and the corresponding frequencies of the body coupled with an elastic seat compared with those measured with the rigid seats. The peak AM magnitude with the elastic seat increased with increase in the vertical vibration magnitude, while effect was very small with the rigid seats (Mansfield and Griffin 2000;Wang, Rakheja, and Boileau 2004;Dewangan et al 2013b).…”

“…The force plate and acceleration signals were analysed to obtain AM response using the H 1 frequency response function method, which was inertia corrected to account for contributions of the rigid seat mounted on the force plate (Wang, Rakheja, and Boileau 2004;Dewangan et al 2013b). The AM response of each subject seated on the rigid seat was also computed from seat pressure mat.…”

Operator's reaction time prolongation induced by whole-body vibration

“…The frequencies were selected to cover a wide range, with particular attention on 5 Hz, since previous studies [38][39][40] found primary resonance frequency of seated subject in the range of 4 to 6 Hz.…”