Authors
Xu XS; Dong RG; Welcome DE; Warren C; McDowell TW; Wu JZ
Source
Int J Ind Ergon 2017 Nov; 62:1-12
Abstract
Some powered hand tools can generate significant vibration at frequencies below 25 Hz. It is not clear whether such vibration can be effectively transmitted to the upper arm, shoulder, neck, and head and cause adverse effects in these substructures. The objective of this study is to investigate the vibration transmission from the human hands to these substructures. Eight human subjects participated in the experiment, which was conducted on a 1-D vibration test system. Unlike many vibration transmission studies, both the right and left hand-arm systems were simultaneously exposed to the vibration to simulate a working posture in the experiment. A laser vibrometer and three accelerometers were used to measure the vibration transmitted to the substructures. The apparent mass at the palm of each hand was also measured to help in understanding the transmitted vibration and biodynamic response. This study found that the upper arm resonance frequency was 7e12 Hz, the shoulder resonance was 7e9 Hz, and the back and neck resonances were 6e7 Hz. The responses were affected by the hand-arm posture, applied hand force, and vibration magnitude. The transmissibility measured on the upper arm had a trend similar to that of the apparent mass measured at the palm in their major resonant frequency ranges. The implications of the results are discussed. Relevance to industry: Musculoskeletal disorders (MSDs) of the shoulder and neck are important issues among many workers. Many of these workers use heavy-duty powered hand tools. The combined mechanical loads and vibration exposures are among the major factors contributing to the development of MSDs. The vibration characteristics of the body segments examined in this study can be used to help understand MSDs and to help develop more effective intervention methods.
Keywords
Vibration; Vibration effects; Vibration exposure; Hand-arm vibration syndrome; HAVS; Body regions; Humans; Musculoskeletal system; Musculoskeletal system disorders; MSD; Arm injuries; Hand injuries; Hand tools; Head injuries; Neck injuries; Power tools; Physiological measurements; Physiological testing; Acceleration; Lasers; Biodynamics; Analytical instruments; Back injuries; Posture; Force; Body mechanics; Heavy equipment;
Author Keywords: Hand-arm vibration; Hand-transmitted vibration; Shoulder; Neck; Head
Contact
Xueyan S. Xu, ECTB/HELD/NIOSH/CDC, 1095 Willowdale Road, MS L-2027, Morgantown, WV 26505, USA
Document Type
Journal Article
Email Address
XueyanXu@cdc.gov
Priority Area
Construction; Manufacturing
Source Name
International Journal of Industrial Ergonomics
