Transmission of fore-and-aft floor vibration to the spine and head of standing people

Abstract

Sixteen standing male participants were subjected to fore-and-aft sinusoidal vibration with peak magnitude and frequency in the range 0.44–4.431 ms⁻² and 2–6 Hz, respectively. The fore-and-aft, lateral and vertical transmissibilities to the first dorsal vertebra (T1), eighth dorsal vertebra (T8), twelfth dorsal vertebra (T12), fourth lumbar vertebra (L4) and head were measured. Large inter-participant variability was observed in the transmissibilities at all locations. Nevertheless, peaks in the range 3–4.5 Hz were identified at all locations, implying a whole-body resonance in this frequency range. The response was found dominant in the mid-sagittal plane as the lateral transmissibility showed low values. Below 4.5 Hz, the fore-and-aft transmissibility increased with moving from caudal to cranial locations of the upper body. However, at higher frequencies, the opposite trend was observed. The results can be used for developing models that may help understand how vibration affects health and comfort.

KEYWORDS:

• Biomechanics
• transmissibility
• fore-and-aft vibration
• standing
• spine

Acknowledgements

The authors are thankful to engineers Husameldin Aly, Abdullah Alchakouch and Ismaeil Khorsheed for helping with data collection. The authors would like also to thank engineer Sadeque Hamdan for help in preparing the MATLAB files. Many thanks to all participants who took part in this experiment.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was sponsored by the University of Sharjah [Internal Grant No.: 1602040839-P].