Effects of dynamic office chairs on trunk kinematics, trunk extensor EMG and spinal shrinkage

Abstract

To cite this Article van DieËn, J. H. , De Looze, M. P. and Hermans, V. (2001) 'Effects of dynamic office chairs on trunk kinematics, trunk extensor EMG and spinal shrinkage ', Ergonomics, 44: 7,[739][740][741][742][743][744][745][746][747][748][749][750] To link to this Article: DOI: 10.1080/00140130120297 URL: http://dx.doi.org/10.1080/00140130120297Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden.The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Seated work has been shown to constitute a risk factor for low-back pain. This is attributed to the prolonged and monotonous low-level mechanical load imposed by a seated posture. To evaluate the potential health eOE ects with respect to the low back of o ce chairs with a movable seat and back rest, trunk kinematics, erector spinae EMG, spinal shrinkage and local discomfort were assessed in 10 subjects performing simulated o ce work. On three separate occasions subjects performed a 3 h task consisting of word processing, computer-aided design and reading. Three chairs were used, one with a ® xed seat and back rest and two dynamic chairs, one with a seat and back rest movable in a ® xed ratio with respect to each other, and one with a freely movable seat and back rest. Spinal shrinkage measurements showed a larger stature gain when working on the two dynamic chairs as compared with working on the chair with ® xed seat and back rest. Trunk kinematics and erector spinae EMG were strongly aOE ected by the task performed but not by the chair type. The results imply that dynamic o ce chairs oOE er a potential advantage over ® xed chairs, but the eOE ects of the task on the indicators of trunk load investigated were more pronounced than the eOE ects of the chair. EOE ects of dynamic o ce chairs on trunk kinematics

Application of Machine Learning Approaches for Classifying Sitting Posture Based on Force and Acceleration Sensors

“…Chronic low back pain (LBP) is one such musculoskeletal disorder that is commonplace, with almost everyone experiencing it at one time or the other [4]. Prolonged periods of sitting hinder or restrict the movement of the lower spine and, therefore, prevent changes in the hydrostatic pressure in the intervertebral discs and seem to be detrimental for nutrition of the vertebral disc [5–7]. Krämer [8] reported that periodic changes in the loads of the intervertebral discs are critically important for not only their nutrition but also resistance against pathological changes, since frequent changes between high and low disc loads are able to induce an effective pump mechanism in the vertebral discs [9].…”

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Smart Chair for Monitoring of Sitting Behavior

“…The sitting behavior analysis becomes an important research topic recently in a variety of domains, such as biomedical engineering, public healthcare service and facility design. It has been suggested that poor sitting behaviour can cause a threat to human body by linking to various pains and other complications [1,2]. Previous studies have showed that some common sitting postures of human body can lead to lumbar flexion and higher compressive forces in lumbar joints [2,3].…”