Effects of a Ball-Backrest Chair on the Muscles Associated With Upper Crossed Syndrome When Working at a VDTBy Yoo, Won-gyu; Yi, Chung-whi; Kim, Min-hee; Work: A Journal of Prevention, Assessment & Rehabilitation, Vol. 29, pp. 239-244
Publication Date: 2007
Study examined the effect of a ball-backrest chair on the weakness and tightness of muscles associated with upper crossed syndrome when working at a visual display terminal (VDT). Surface electromyography (EMG) was recorded from the serratus anterior and the middle and upper trapezius muscles, known as the weakened and tightened muscles of upper crossed syndrome, of 13 male and 7 female adults aged 21-26 years and free of any pre-existing neck or back pain. Participants typed randomly-selected work on a computer, seated on a general-purpose-backrest chair and a chair with a forward-protracting ball backrest exerting a continuous external load using the tension of the ball against the upper spinal tissues. The significance of differences between the use of a general-purpose backrest and a ball backrest was tested by a paired t-test. The activities of the serratus anterior and middle trapezius muscles were found to increase when sitting in a ball-backrest chair as compared to sitting in a chair with general-purpose backrest, indicating that the use of a ball-backrest chair reduces the risk of patients with upper cross syndrome developing muscle soreness or injury related to overuse when working at a VDT.
Published by: IOS Press (Website:http://www.iospress.nl)