Experimental investigation of biodynamic human body models subjected to whole-body vibration during a vehicle ride

Whole body vibration (WBV) is uncontrolled vibrations in occupational settings such as vehicle driving or hand tool operating. Chronic occupational WBV exposure may cause many health problems such as fatigue, lower back pain, spinal degenerations, vision problems and so on. In order to simulate and observe the adverse effects of WBV on the human body, many lumped-parameter human body models were proposed. The objective of this study is to provide quantified assessments of human body biodynamic models which were designed to characterize the response of real human body exposed to WBV. To do so, direct measurements of vibration accelerations obtained from different segments of human body and vehicle seat were carried out during riding on roads with different unevenness levels. Recorded experimental acceleration data were compared with those obtained from simulations of different human body models. Root mean square difference and correlation coefficient values were calculated between theoretical and experimental accelerations for a quantitative assessment of the existing models. According to the comparison results, biodynamic model proposed by Boileau and Rakheja [Boileau P-É, Rakheja S, Whole-body vertical biodynamic response characteristics of the seated vehicle driver: Measurement and model development, Int J Ind Ergonom22:449–472, 1998] showed the best correlation with the experimental acceleration data.

Download Full-text

Mechanical impedance of the sitting human body in single-axis compared to multi-axis whole-body vibration exposure

Clinical Biomechanics ◽

10.1016/s0268-0033(00)00102-9 ◽

2001 ◽

Vol 16 ◽

pp. S101-S110 ◽

Cited By ~ 23

Author(s):

Patrik Holmlund ◽

Ronnie Lundström

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Mechanical Impedance ◽

Whole Body ◽

Vibration Exposure ◽

Body Vibration

Download Full-text

Modeling of Spinal Column of Seated Human Body under Exposure to Whole-Body Vibration

Journal of System Design and Dynamics ◽

10.1299/jsdd.2.1327 ◽

2008 ◽

Vol 2 (6) ◽

pp. 1327-1338

Author(s):

Gen TAMAOKI ◽

Takuya YOSHIMURA ◽

Kaoru KURIYAMA ◽

Kazuma NAKAI

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Spinal Column ◽

Whole Body ◽

Body Vibration

Download Full-text

Power Absorbed by the Standing Human Body During Whole-Body Vibration Training

Journal of Biomechanical Engineering ◽

10.1115/1.4045809 ◽

2020 ◽

Vol 142 (7) ◽

Author(s):

Naser Nawayseh ◽

Sadeque Hamdan

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Whole Body ◽

Apparent Mass ◽

Input Frequency ◽

Knee Angle ◽

Body Vibration ◽

Training Conditions ◽

Vibration Training ◽

Whole Body Vibration Training

Abstract Absorbed power (AP) is a biodynamic response that is directly related to the magnitude and duration of vibration. No work has previously investigated the power absorbed by the standing human body during the exposure to vibration training conditions or otherwise. This article reports the power absorbed by the standing human body under whole-body vibration (WBV) training conditions. In this work, the force and acceleration used to calculate the apparent mass by Nawayseh and Hamdan (2019, “Apparent Mass of the Standing Human Body When Using a Whole-Body Vibration Training Machine: Effect of Knee Angle and Input Frequency,” J. Biomech., 82, pp. 291–298) were reanalyzed to obtain the AP. The reported acceleration was integrated to obtain the velocity needed to calculate the AP. The effects of bending the knees (knee angles of 180 deg, 165 deg, 150 deg, and 135 deg) and vibration frequency (17–42 Hz) on the power absorbed by 12 standing subjects were investigated. Due to the different vibration magnitudes at different frequencies, the AP was normalized by dividing it by the power spectral density (PSD) of the input acceleration to obtain the normalized AP (NAP). The results showed a dependency of the data on the input frequency as well as the knee angle. A peak in the data was observed between 20 and 24 Hz. Below and above the peak, the AP and NAP tend to increase with more bending of the knees indicating an increase in the damping of the system. This may indicate the need for an optimal knee angle during WBV training to prevent possible injuries especially with prolonged exposure to vibration at high vibration intensities.

Download Full-text

Transmission of Vertical Whole Body Vibration to the Human Body

Journal of Bone and Mineral Research ◽

10.1359/jbmr.080315 ◽

2008 ◽

Vol 23 (8) ◽

pp. 1318-1325 ◽

Cited By ~ 129

Author(s):

Juha Kiiski ◽

Ari Heinonen ◽

Teppo L Järvinen ◽

Pekka Kannus ◽

Harri Sievänen

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Whole Body ◽

Body Vibration

Download Full-text

Biodynamics of the human body under whole-body vibration: Synthesis of the reported data

International Journal of Industrial Ergonomics ◽

10.1016/j.ergon.2010.06.005 ◽

2010 ◽

Vol 40 (6) ◽

pp. 710-732 ◽

Cited By ~ 62

Author(s):

S. Rakheja ◽

R.G. Dong ◽

S. Patra ◽

P.-É. Boileau ◽

P. Marcotte ◽

...

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Whole Body ◽

Body Vibration ◽

Reported Data

Download Full-text

Modelling the apparent mass of the standing human body under whole-body vibration training conditions

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411920917311 ◽

2020 ◽

Vol 234 (7) ◽

pp. 697-710

Author(s):

Naser Nawayseh ◽

Sadeque Hamdan ◽

Mario Bernardo-Filho ◽

Redha Taiar

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Whole Body ◽

Design Stage ◽

Model Parameters ◽

Apparent Mass ◽

Body Vibration ◽

Training Conditions ◽

Vibration Training ◽

Whole Body Vibration Training

Several studies have measured the vibration transmitted to and through the human body under vibration training conditions. However, no work has modelled the apparent mass of the human body under such conditions. In this work, a 2 degree-of-freedom model has been developed to predict the apparent mass of the standing human body under whole-body vibration training conditions. The parameters of the model were optimised using measured apparent mass of 12 subjects standing with different knee angle of 180°, 165°, 150° and 135°. Good agreement was found between the predicted and measured apparent mass with errors less than 3 kg in the median apparent mass magnitude and errors less than 6° in the apparent mass phase angle. The medians of the optimised parameters of the 12 individual apparent masses were close to the corresponding optimised parameters of the median apparent mass of the 12 subjects. Compared to standing with extended legs, bending the knees was found to affect mainly the parameters (i.e. stiffness and damping) of the model close to the source of vibration. Bending the knees decreased the mass of the model close to the source of vibration and increased the mass away from the source of vibration. Among the postures with bent knees, the change in the model parameters was generally not significant. The model can be used as a tool by manufacturers of whole-body vibration training machines to test the performance of the machines during the design stage and/or after production. This will decrease the number of experimentations with human subjects which guarantees consistency, repeatability, time-saving and safety.

Download Full-text

Localised apparent masses over the interface between a seated human body and a soft seat during vertical whole-body vibration

Journal of Biomechanics ◽

10.1016/j.jbiomech.2020.109887 ◽

2020 ◽

Vol 109 ◽

pp. 109887

Author(s):

Chi Liu ◽

Yi Qiu

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Whole Body ◽

Body Vibration

Download Full-text

Biodynamic Responses to Whole-Body Vibration Training: A Systematic Review

Journal of Applied Biomechanics ◽

10.1123/jab.2020-0365 ◽

2021 ◽

pp. 1-14

Author(s):

Naser Nawayseh ◽

Saleh AlBaiti

Keyword(s):

Human Body ◽

Whole Body Vibration ◽

Whole Body ◽

Extensive Literature ◽

Apparent Mass ◽

Inclusion Criteria ◽

Body Vibration ◽

Extensive Literature Search ◽

Vibration Training ◽

Whole Body Vibration Training

In recent years, whole-body vibration (WBV) training has received an increasing interest in the sports and medical fields. However, there has been inconsistency among several studies regarding the effect of WBV training on the human body, which is partly due to the lack of the existence of guidelines for using WBV training machines. To understand the effect of WBV training on the human body and build the needed regulations, it is essential first to understand the biodynamic responses to vibration which represent how vibration is transmitted to and through the human body. The purpose of this study is to systematically review previous studies that measured biodynamic responses when using WBV training machines to highlight inconsistencies in their results and provide possible reasons for them. An extensive literature search was performed on the SCOPUS database to obtain relevant studies. One hundred and fifty-six potentially relevant studies were obtained but after further screening, 23 papers from 2007 to 2020 met inclusion criteria and were included in the study. The papers were analysed with respect to acceleration, transmissibility, interface force, and apparent mass during different vibration settings, body posture, age, and sex. Results and conflicts among studies were highlighted and possible explanations for the inconsistency were provided.

Download Full-text