Evaluation of psychometric estimates of vibratory hand-tool grip and push forces.
McDowell-TW; Wiker-SF; Dong-RG; Welcome-DE; Schopper-AW
Int J Ind Ergon 2006 Feb; 36(2):119-128
Tool grip and push forces are important determinants of health risk associated with operation of powered hand tools. In the field, use of sophisticated hand-force instrumentation can be impractical. This study investigated the potential for using psychophysical force recall methods to estimate grip and push forces when operating vibratory hand tools. This study examined various combinations of handle vibration and grip and push force exposures upon one's ability to recall those forces using psychophysical methods. Twelve male subjects grasped and pushed an instrumented handle for 45 s at one of three levels of force while it vibrated sinusoidally at one of five frequencies (0, 12.5, 40, 125, or 250 Hz). We examined the effects of post-exertion rest periods of 10 and 20 s upon force recall performance, and day-to-day test-retest reliability. Results showed vibration frequency and force level differentially influenced grip and push force recall accuracy. Subjects characteristically overestimated grip and push forces; especially during vibration exposures of 40 and 125 Hz. The magnitude of the overestimations increased as target force levels decreased. Test-retest correlations were reasonably strong.
Tools; Hand-tools; Vibration; Vibration-exposure; Vibration-disease; Hand-injuries; Risk-factors; Risk-analysis; Exposure-assessment
National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Engineering & Control Technology Branch, 1095 Willowdale Road, Morgantown, MS 2027, WV 26505, USA
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
International Journal of Industrial Ergonomics