This present study is devoted to investigate the vibration transmissibility of the elbow along the forearm direction as a function of hand grip force. The vibration was from 6 to 500 Hz, which was generated on a single-axis electric shaker. It was transmitted to the elbow from an instrumented handle fixed on the shaker through the hand-arm system. 34 healthy adults participated in the measurement experiment. Each of them applied a constant grip force while maintaining the forearm in horizontal direction with a 90° elbow angle. The grip force was controlled in terms of the percent maximum voluntary contraction and three levels (20%, 30% and 40%) most frequently observed at workplaces were used in the experiment. A laser vibrometer was used to measure the vibration on the bony surface of the elbow along the forearm direction. The measured vibration transmissibility spectrum was expressed in an equal frequency band with a resolution of less than 1 Hz. This study found that increasing the grip force did not significantly change the first resonant peak at 8 Hz but it increased the second resonant frequency and the vibration transmissibility at higher frequencies.
Relevance to industry: The effect of the grip force on the elbow vibration transmissibility can be used to enhance the understanding of the vibration-induced disorders. The force-specific transmissibility can also be used as a frequency-weighting factor to quantify the exposure. They may help improve the method for the risk assessment of vibration-induced elbow injuries and disorders.
|2010||Adewusi SA, Rakheja S, Marcotte P, Boutin J. Vibration transmissibility characteristics of the human hand–arm system under different postures, hand forces and excitation levels. J Sound Vibrat. July 5, 2010;329(14):2953-2971.|
|2004||Dong RG, Schopper AW, McDowell TW, Welcome DE, Wu JZ, Smutz WP, Warren C, Rakheja S. Vibration energy absorption (VEA) in human fingers-hand-arm system. Med Eng Phys. July 2004;26(6):483-492.|
|1995||Kihlberg S. Biodynamic response of the hand-arm system to vibration from an impact hammer and a grinder. Int J Ind Ergon. July 1995;16(1):1-8.|
|1986||Sakakibara H, Kondo T, Miyao M, Yamada S, Nakagawa T, Kobayashi F, Ono Y. Transmission of hand-arm vibration to the head. Scand J Work Environ Health. August 1986;12(4):359-361.|
|1976||Pyykkö I, Färkkilä M, Toivanen J, Korhonen O, Hyvärinen J. Transmission of vibration in the hand-arm system with special reference to changes in compression force and acceleration. Scand J Work Environ Health. June 1976;2(2):87-95.|
|1977||Reynolds DD, Angevine EN. Hand-arm vibration, II: vibration transmission characteristics of the hand and arm. J Sound Vibrat. March 22, 1977;51(2):255-265.|