The Experimental Study Of Rectifying The Sitting Posture When Reading A Book By The Mean Of The Different Width Gaps Glasses For Controlling The Visual Field

ObjectiveAppling the different width of silt controller adjusts the college students'sitting posture when reading the book. Research the change of their body posture during the period, and find the relative rule that is applied to rectify their reading posture. What width is silt controller can attain the standard reading posture for the people who have the nearly same height.Materials and methodsSubjects were 18 people. There are 4 groups which are 1mm,2mm,3mm and 4mm width of silt controller respectively. The data is collected by the mean of the Vicon three-dimensional trajectories of the infrared camera system (England). Reading the book lasts for 2 minutes. Makers are adhered to the midpoint of the paper, C7, bilaterally over the outer canthus of the eyes, external auditory meatus, posterior acromial shelf, and the femoral greater trochanter. Calculated parameters include neck flexion, head flexion, cranio-cervical angle, cervico-thoracic angle, gaze angle, the absolute reading distance and the relative reading distance. Measure the length of the forearm of the subjects in order to calculate the relative reading distance. Appling these parameters illustrate the change of subjects'neck and trunk in the vertical plane when reading books. sEMG was collected from the cervical erector spinae(CES) and upper trapezius (UT) muscles.The starting 30s data of the Vicon and the total 2 minutes'sEMG data reflect the change of 3-D posture and muscle activity around the neck and shoulder.ResultsThere are 1mm,2mm,3mm and 4mm different width of silt glasses, when the width are larger, the absolute reading distance and relative reading distance are smaller, and the head flexion are smaller. The relative reading distance of the 2mm width gaps glass is significant correlated with the standard reading posture.(r=.792). The cranio-cervical angle and cervico-thoracic angle of the 1mm width gaps glass is significant correlated with the standard reading posture.(r=.789, r=.679 respectively) There are not significant in the %MVC of upper trapezius muscle between any two different width gaps glasses.%MVC of upper trapezius muscle of the 2mm width gap glass is the strongest one; the 1mm width gap glass is the weakest one.ConclusionAdjust the reading distance of readers by the mean of the width of the silt glass in order to prevent the myopia. In the cases of four different width of silt glasses, 2mm width silt is the best one in terms of the relative reading distance, and 1mm width silt is the best one in terms of neck and trunk in order to attain standard reading posture.