Study On The Comfort Of Round-backed Armchair's Round Back

In the study, we conduct a concrete analysis of influencing factors on round back's com-fortableness, through extensive literature collection which based on ergonomic,then initially constructs a theoretical basis of round back research. And we take a series of experiments to get the best degree of comfortableness, by researching on the height of round back,the max di-ameter of round back,and the inclination angle of round back. We use sEMG as objectives re-search method, and combined with subjective experimental result,conduct a quantitative analy-sis. The results of experiment showed:(1) People pay more emphasis of using the round-backed armchair to human physiologi-cal and psychological reactions. In the round back's design,the structure of structural modeling, the size and the production process must be based on people's needs,and must be consistent with human physiology and human activities in various parts of the body. But the materials se-lection, wood grain selection, should be taken more consideration of people's psychological needs. Among them, the height of round back, the max diameter of round back and the inclina-tion angle of round back, are the greatest impact factors on the use of comfortableness.(2) When the height of round back is 440mm,480mm or 520 mm, as the experimental time add, the testee's fatigue degree in shoulder, arm and waist all increases.When the height of round back is 480mm,the comfortableness of people is the highest;when the height of round back is 520mm, the comfortableness of people is taken a second place;when the height of round back is 440mm,the comfortableness of people is the worst.(3) When the max diameter of round back is 610mm,650mm or 690 mm, when the max diameter of round back is 610mm,the comfortableness of people is the highest;when the max diameter of round back is 650mm,the comfortableness of people is take a second place;when the max diameter of round back is 690mm,the comfortableness of people is the worst.(4) When the inclination angle of round back is 25°,30°or 35°,when the inclination angle of round back is 25°, the comfortableness of testee's shoulders,arm and waist is the high-est,this means,the comfortableness of human body is the highest. When the inclination angle of round back is 30°, the comfortableness of testee a second place.When the inclination angle of round back is 35°, the comfortableness of testee is the worst.(5) We can find from the subjective evaluation form, the testee's arm fatigue strength degree is above. So we can draw a conclusion,in the research of round-backed armchair's round back,the testee's arms are easily fatigued when they keep sitting, also the result of subjective evaluation is in agreement with the sEMG experiment.