Biodynamic response of the human body in the sitting position when subjected to vertical vibration

Donati, Patrice; Bonthoux, C.

doi:10.1016/0022-460x(83)90723-x

Cited by 22 publications

(15 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These are attributable to differences in the measurement systems, vibration type and magnitude, posture, involuntary changes in muscle tension and the physical attributes of subjects used in different studies [2,7,8]. Moreover, the reported STHT responses exhibit substantially large inter-subject variability, which may be partly caused by differences in measurement systems and physical characteristics of the subjects [9]. The physical characteristics among the humans are known to vary widely and the differences are far more important between the male and female populations.…”

Section: Introductionmentioning

confidence: 99%

Vertical and Fore-Aft Seat-to-Head Transmissibility Response to Vertical Whole Body Vibration: Gender and Anthropometric Effects

Dewangan

Shahmir

Rakheja

et al. 2013

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

In this study, the biodynamic responses to vertical vibration are investigated in terms of seat-to-head vibration transmissibility (STHT) to study the effects of gender and eleven different anthropometric parameters on the STHT responses in the vertical and fore-aft directions. The STHT response of 31 male and 27 female human subjects were measured under three levels of vertical vibration (0.25, 0.50 and 0.75 m/s 2 rms acceleration) in the 0.50 to 20 Hz range, while seated without a back support and against a vertical back support with hands on a steering wheel. The results showed that the vertical and fore-aft STHT responses of the two genders were distinctly different. The primary resonance frequency of the male subjects was higher than the female subjects, while the peak magnitudes were comparable. The male subjects showed relatively greater softening effect, i.e. decrease in the primary resonance frequency with increase in excitation magnitude, as compared to the female subjects, irrespective of the sitting condition. The body mass revealed strong effect on both the male and female STHT responses. The primary resonance frequency of heavier subjects was lower than that of the lighter subjects, while the peak magnitude was higher for the heavier subjects. The male subjects showed significantly higher primary resonance frequency than the female subjects, even when comparable body mass, BMI and lean body mass were considered. The vertical STHT response of the two genders with same body fat mass was very similar for the sitting and excitation conditions considered in the study, particularly up to 10 Hz.

show abstract

Section: Introductionmentioning

confidence: 99%

Vertical and Fore-Aft Seat-to-Head Transmissibility Response to Vertical Whole Body Vibration: Gender and Anthropometric Effects

Dewangan

Shahmir

Rakheja

et al. 2013

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

show abstract

“…In general, the inter-subject variation refers to the physical difference between subjects, e.g., body mass, age and gender, while the intra-subject variation refers to the change in an individual's response over time, either from one moment to another or over a much longer period (1) . Many studies investigated the change in human responses under various experimental conditions, in which experiments were conducted under various experimental conditions using many subjects and the inter-subject variation was evaluated (4)- (13) . In ISO 5982, the biodynamic responses of a seated human are also based on inter-subject variation when the subjects exposed to WBV at different excitation amplitudes or different postures (1), (7) .…”

Section: Introductionmentioning

confidence: 99%

“…Normalization of Intra-subject variation "over several days" Normalization of apparent mass of comparison between the total value of SD ( total σ ) "within a day" (black) and that the baseline (white) (a), Comparison of the total value of SD ( total σ ) "over several days" (gray) that of the baseline (white) (b)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) …”

mentioning

confidence: 99%

Validation of Intra-Subject Variation in Biodynamic Responses of Seated Human Exposed to Whole-Body Vibration

Park

Yoshimura

Tamaoki

2012

JSDD

View full text Add to dashboard Cite

Many studies have been conducted to investigate the change in human response under various experimental conditions. Usually, these experiments were conducted using many subjects and the inter-subject variation was evaluated. However, the intra-subject variation in human response is also necessary for understanding the change in an individual's physical response to whole-body vibration (WBV). The aim of this study is to investigate the intra-subject variation in biodynamic responses (both apparent mass and seat-to-head transmissibility) of a seated human exposed to vertical whole-body vibration over time. In the experiments, nine male subjects were exposed to vertical random vibration (0.2-0.3 m/s 2 in r.m.s.) in the 0-30Hz frequency range. The measurement variation was also evaluated, wherein the measurements were repeated five times without any change to form the "baseline" for each subject, and the intra-subject variations were evaluated by comparing their responses with these "baseline." The intra-subject variation was examined from two different viewpoints: variation "within a day" and that "over several days." To determine the intra-subject variation "within a day", the five measurements were obtained at two-hour intervals on the same day. In the intra-subject variation "over several days", the five measurements were obtained again, but at the same time of the day on five consecutive days. The results show that the intra-subject variations (both "within a day" and "over several days") in biodynamic responses are larger than the "baseline." However, when the variation "within a day" in biodynamic responses is compared to that "over several days," no common trend is observed among subjects. Although the magnitude of intra-subject variation in biodynamic responses depends on each subject, both variations "within a day" and that "over several days" have a similar range of variation.

show abstract

“…These results are in broad agreement with those obtained by Lewis and Griffin 42 who reported that contact with the backrest increased the transmission of X-axis seat motion to the head at frequencies above about 5 Hz. Donati and Bonthous 43 found that the presence of a seat back, in the form of a lumber support, increased discomfort between 3 and 6 Hz. Apart from the back support, the hands on lap support also help maintain a stable sitting posture under horizontal vibration.…”

Section: Griffinmentioning

confidence: 99%

Effects of posture and vibration magnitude on seat to head transmissibility during exposure to fore-and-aft vibration

Bhiwapurkar¹,

Saran

Harsha

2018

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

An experimental study has been conducted on the vibration simulator, developed as a mockup of a railway vehicle. In this paper, the effect of variations in the posture and vibration magnitude on head motions in three translational directions (fore-and-aft, lateral and vertical) are studied with seat vibration in fore-and-aft direction. Thirty healthy male subjects are exposed to random vibration with three vibration magnitudes of 0.4, 0.8 and 1.2 m/s 2 r.m.s. over the frequency range 1-20 Hz. The data results are analyzed in terms of seat-to-head transmissibility (STHT) in two sitting postures; backrest and forward lean. Vibration measurements of the head motions are made with an apparatus (bite-bar). The study confirms that the measured responses to single fore-and-aft axis vibration have shown notable cross-axis responses. An increase in the excitation magnitude consistently revealed a decrease in the response peak magnitude and the corresponding resonant frequency, particularly in the presence of a back support. Such non-linear behavior has been interpreted as a non-linear softening effect in the muscle tension under increasing intensity of vibration. The use of a back support significantly alters the biodynamic responses of the seated body, which is attributable to the constraint due to the backrest support.

show abstract

Biodynamic response of the human body in the sitting position when subjected to vertical vibration

Cited by 22 publications

References 1 publication

Vertical and Fore-Aft Seat-to-Head Transmissibility Response to Vertical Whole Body Vibration: Gender and Anthropometric Effects

Vertical and Fore-Aft Seat-to-Head Transmissibility Response to Vertical Whole Body Vibration: Gender and Anthropometric Effects

Validation of Intra-Subject Variation in Biodynamic Responses of Seated Human Exposed to Whole-Body Vibration

Effects of posture and vibration magnitude on seat to head transmissibility during exposure to fore-and-aft vibration

Contact Info

Product

Resources

About