Conclusions and recommendations
In addition to confirm of the former researchers findings [25], this result have shown that ergonomic standard used in schools furniture-making include desk and bench height, padding height, desk and bench slop and blackboard height are not proportional with the users anthropometrics dimensions. And not only can causes to early fatigue, cervical, backbone and lumbar pain and reducing in efficiency, but also may causes to incidence of postural disorder in long term such as: forward head, scoliosis, hypnosis and lordosis. Because long sitting of most students in sitting and static position at school. In this direction, in order to suitable use of mentioned furniture, right sitting and displacing their situation on behalf of the teacher, especially from physical training teachers can proceed required help to improvement of school users. Also it seems that with small change in making the desk and chair surface and back of the benches may create standard slope. Design of chairs, benches, desk and desk inclination, chair inclination if may changeable and displaceable in height by users and teachers seems possible by creating a hole and the use of thin bars and will not have any extra expenses. Select a good posture for student when use of the classroom furniture is very important for prevention of fatigue upon student body. A chair with fixed dimensions is suitable for the vast majority of the children in the same class; a desk with fixed dimensions is suitable for the majority of students in the same class.