A comparison of biodynamic models of the human hand-arm system for applications to hand-held power tools.
Rakheja S; Wu JZ; Dong RG; Schopper AW; Boileau PE
J Sound Vib 2002 Jan; 249(1):55-82
The biodynamic response characteristics of various mechanical models of the human hand and arm system, reported in the literature, are evaluated in terms of their driving-point mechanical impedance modulus and phase responses. The suitability of the reported models for applications in realizing a mechanical simulator and assessment of vibration behavior of hand-held power tools is examined using three different criteria. These include the ability of the model to characterize the driving-point mechanical impedance of the human hand-arm system within the range of idealized values presented in ISO-10068 (1998); the magnitude of model deflection under a static feed force; and the vibration properties of the human hand and arm evaluated in terms of natural frequencies and damping ratios. From the relative evaluations of 12 different models, it is concluded that a vast majority of these models cannot be applied for the development of a mechanical hand-arm simulator or the assessment of dynamic behavior of the coupled hand-tool system. The higher order models, with three and four degrees of freedom, in general, yield impedance characteristics within the range of idealized values, but exhibit excessive static deflections. Moreover, these models involve very light masses (in the 1·2-4·8 g range), and exhibit either one or two vibration modes at frequencies below 10 Hz. The majority of the lower order models yield reasonable magnitudes of static deflections but relatively poor agreement with idealized values of driving-point mechanical impedance.
Biodynamics; Models; Power-tools; Hand-tools; Hand-protection; Vibration-monitors
Engineering and Control Technology Branch, NIOSH, 1095 Willowdale Road, MS 2027, Morgantown, WV 26505, USA
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities; Research Tools and Approaches: Control Technology and Personal Protective Equipment
Journal of Sound and Vibration