%0 Journal Article %1 keyhere %A Szeto, Grace P.Y. %A Straker, Leon M. %A O'Sullivan, Peter B. %D 2005 %J International Journal of Industrial Ergonomics %K Computer Electromyography Motor Office Physical Work-related and control disorders ergonomics limb neck stressors upper use %N 5 %P 429--444 %T The effects of speed and force of keyboard operation on neck-shoulder muscle activities in symptomatic and asymptomatic office workers %U http://www.sciencedirect.com/science/article/B6V31-4F1JP44-1/2/80f46e3c39d03267eb9f661c1cf7548c %V 35 %X The study compared the EMG changes and discomforts experienced by a symptomatic and an asymptomatic group of office workers when they were challenged by the physical stressors of increased typing speed and increased typing force. 21 female office workers were recruited in the Case Group and 20 in the Control Group. Each subject had to perform 20 min of typing in 3 conditions: Normal, Faster and Harder; which described the requirement to work with normal speed and force, faster speed and harder force, respectively. The Case Group showed trends for higher muscle activities in all three conditions in both the upper trapezius and cervical erector spinae muscles. On the whole, there were greater increases in muscle activities in both groups under the Faster condition, implying that increasing the typing speed was a more difficult demand. When the Case subjects were sub-divided into High and Low (Discomfort) Groups, greater differences in muscle activities were revealed. It was mainly the High Group that showed the greatest changes in terms of muscle activities and discomforts. The Low Group showed moderate increases in discomforts and muscle activities, while the Control Group showed minimal changes in both. The results supported the Ältered Motor Control" model in the symptomatic individuals who may also have developed a "heightened sensitivity" to physical stressors due to their prolonged history of discomforts in the past.Relevance to industry The study demonstrated different reactions of symptomatic and asymptomatic office workers when they were subjected to the same physical stressors. These inter-individual differences in physiological and psychological responses should be considered when ergonomic interventions are introduced. The results also demonstrated that the factors of speed and force of keyboard operation may have important influences on the muscle activities and discomforts in computer users.

@article{keyhere, abstract = {The study compared the EMG changes and discomforts experienced by a symptomatic and an asymptomatic group of office workers when they were challenged by the physical stressors of increased typing speed and increased typing force. 21 female office workers were recruited in the Case Group and 20 in the Control Group. Each subject had to perform 20 min of typing in 3 conditions: Normal, Faster and Harder; which described the requirement to work with normal speed and force, faster speed and harder force, respectively. The Case Group showed trends for higher muscle activities in all three conditions in both the upper trapezius and cervical erector spinae muscles. On the whole, there were greater increases in muscle activities in both groups under the Faster condition, implying that increasing the typing speed was a more difficult demand. When the Case subjects were sub-divided into High and Low (Discomfort) Groups, greater differences in muscle activities were revealed. It was mainly the High Group that showed the greatest changes in terms of muscle activities and discomforts. The Low Group showed moderate increases in discomforts and muscle activities, while the Control Group showed minimal changes in both. The results supported the "Altered Motor Control" model in the symptomatic individuals who may also have developed a "heightened sensitivity" to physical stressors due to their prolonged history of discomforts in the past.Relevance to industry The study demonstrated different reactions of symptomatic and asymptomatic office workers when they were subjected to the same physical stressors. These inter-individual differences in physiological and psychological responses should be considered when ergonomic interventions are introduced. The results also demonstrated that the factors of speed and force of keyboard operation may have important influences on the muscle activities and discomforts in computer users.}, added-at = {2007-11-22T17:17:23.000+0100}, author = {Szeto, Grace P.Y. and Straker, Leon M. and O'Sullivan, Peter B.}, biburl = {https://www.bibsonomy.org/bibtex/24cc1f994197a807846b93b2976da8c26/thomaslevine}, interhash = {6ec8b49c1cfc70d2f3ce42142b713392}, intrahash = {4cc1f994197a807846b93b2976da8c26}, journal = {International Journal of Industrial Ergonomics}, keywords = {Computer Electromyography Motor Office Physical Work-related and control disorders ergonomics limb neck stressors upper use}, month = {#may#}, number = 5, pages = {429--444}, timestamp = {2007-11-22T17:17:24.000+0100}, title = {The effects of speed and force of keyboard operation on neck-shoulder muscle activities in symptomatic and asymptomatic office workers}, url = {http://www.sciencedirect.com/science/article/B6V31-4F1JP44-1/2/80f46e3c39d03267eb9f661c1cf7548c}, volume = 35, year = 2005 }