An exploratory study of the relationship between biomechanical factors and right-arm musculoskeletal discomfort and fatigue in a VDT data-entry task.
Appl Ergon 1996 Jun; 27(3):195-200
The relationship of key force and keystroke rate with right arm musculoskeletal discomfort and fatigue was examined in 43 video display terminal (VDT) workers. These workers were all women who served as data transcribers and who had vocational school backgrounds. The numeric keypad of a VDT was used to enter numeric data from simulated tax forms; the subjects used their right hand to perform this task. A compression load cell placed under the '7' key was used to monitor peak key force. Lower key forces were associated with higher ratings of right hand discomfort. Both lower key forces and keystroke rates were associated with higher ratings of right elbow discomfort, accounting for 24% of the variance in this model. A significant correlation existed between fatigue and right shoulder discomfort and right elbow discomfort. No significant relationship between fatigue and right hand discomfort was noted. A significant negative correlation was noted between keystroke rate and musculoskeletal discomfort for some of the work periods at the end of the day. Throughout the work day there were negative correlations between key force and musculoskeletal discomfort for many periods of time. There was a correspondence between the cumulative increase in fatigue and musculoskeletal discomfort across the workday. The authors stress the need for further laboratory and field studies to clarify the direction and extent of the cause and effect relationship between biomechanical factors and musculoskeletal discomfort in this industry.
NIOSH-Author; Office-workers; Keyboard-operators; Ergonomics; Data-processing; Musculoskeletal-system-disorders; Repetitive-work