NIOSHTIC-2 Publications Search
Development of an efficient analytical method for quantifying repetitive motion.
Proceedings of the International Scientific Conference on Prevention of Work-Related Musculoskeletal Disorders, Stockholm, Sweden, May 1992. 1992 May; :237-239
The goal of this project was to develop efficient analytical methods for assessing physical stress and strain associated with hand intensive tasks containing repetitive motion. An attempt was made to use spectral analysis for characterizing task repetitiveness and postural stress. A pilot study was conducted using wrist articular motion. The repetitive task evaluated required using the right hand for inserting discs into a slot aligned with the sagittal plane. Two cycle times were used. The slow rate was paced at 6 seconds/cycle and the fast rate paced at 3 seconds/cycle. The task was repeated 36 times for each condition. Spectrum peaks corresponded closely to the inverse of the subcycle times for both tasks. Peaks were observed at 0.17 hertz (Hz) for the 6 second/cycle task and at 0.33Hz for the 3 second/cycle task. Harmonics corresponded to subcycle movements. A similar relationship held for ulnar/radial deviation. Three relationships were derived from the study. The DC component of the spectrum indicates sustained postures and exertions. Frequency components of the spectrum are proportional to the frequency movement and exertion repetitions. The magnitude at each spectral band indicates the posture and force ranges for corresponding repetition rates.
NIOSH-Grant; Musculoskeletal-system-disorders; Repetitive-work; Task-performance; Physical-stress; Ergonomics; Human-factors-engineering
Industrial Engineering Univ of Wisconsin-Madison 1513 University Ave Madison, WI 53706
Proceedings of the International Scientific Conference on Prevention of Work-Related Musculoskeletal Disorders, Stockholm, Sweden, May 1992
University of Wisconsin Madison, Madison, Wisconsin
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division