Effects of armrests on workload with ten-key operation.
The constrained posture used for work using a visual display terminal (VDT), such as data entry, can produce static muscular fatigue. Based on the application of ergonomic principles, we conducted an experiment using a prototype VDT chair designed with an armrest adjustable to heights from 22 to 28 cm. The experiment--conducted to assess the static muscular strain based on varying heights of the armrest and distance from the keyboard--was performed with male subjects. The subjects were asked to input five-figure numbers using the 10 keys arranged on the right side. Using a surface electromyogram, we measured the strain imposed on the arm and the shoulder. This was followed up with a performance, weight-loading onto the armrests and a questionnaire. Results show that use of armrests is effective for the alleviation of muscles in one-handed keyboard operation where operators work on a desk whose height is unadjustable according to their body height or where operators are unable to rest their wrist on the desk. A chair with height-adjustable armrests is considered desirable when used by several people.
Hasegawa
T
T
Department of Industrial Engineering and Management, Kyushu School of Engineering, Kinki University, Japan.
Kumashiro
M
M
D000328:Adult; D016288:Computer Terminals; D006804:Ergonomics; D005160:Facility Design and Construction; D006801:Humans; D007374:Interior Design and Furnishings; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D016526:Workload