Volume 5, Issue 4 (Journal of Ergonomics 2018)                   Iran J Ergon 2018, 5(4): 17-25 | Back to browse issues page

DOI: 10.30699/jergon.5.4.17

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Professor, Department of Sport Biomechanics, Faculty of Physical Education and Sport Sciences, Bu Ali Sina University, Hamadan, Iran , mehrdadanbarian36@gmail.com
Abstract:   (7634 Views)
Background: Many workers, especially welders, have awkward postures during their working hours. Evaluating such kind of postures is done with the aim of corrective actions. Therefore, the present study was conducted to evaluate the activity of welderchr('39')s muscles in common welding postures working on gas transmission pipelines.
Methods: This cross-sectional descriptive-analytical study was performed on 15 welders of the Iranian Gas Transmission Co. After the required analysis, three postures that were most used working on the gas transmission pipelines were identified to evaluate muscle activity. The surface electromyography (EMG) activity of the erector spinae, biceps femoris, vastus medialis, gastrocnemius medialis, gastrocnemius lateralis, tibialis anterior, rectus abdominis, abdominal internal oblique, abdominal external oblique, and semitendinosus muscles are evaluated in three postures. They are analyzed based on the maximum voluntary contraction (MVC).
Results: The results indicated that the mean of muscle activity in the kneeling posture is significantly lower than two other postures (P<0.001). The mean activity of each muscle in different postures were compared and evaluated. The highest activity was related to the tibialis anterior, vastus medialis and biceps femoris. Abdominal muscles have the lowest activity.
Conclusion: The muscle activity of the welders in the evaluated postures was very high. Based on the findings of this study, the muscle activity was strongly affected by the type of posture and angle of the joints, so  the muscles’ activity in the kneeling posture was lower than the two other postures due to the suitable angle of joints and the direct transmission of body weight.
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Type of Study: Research | Subject: Special
Received: 2018/01/15 | Accepted: 2018/05/19 | ePublished: 2018/05/19