The Effect of a School Backpack Mass Back Carried on the Features of Body Posture in the Frontal Plane of 7-year-old Students of Both Sexes

Abstract

The analysis of the student's environment is a set of stressors in the field of human ecology, which includes not only the genetic factor but also the epigenetic factor. The student's environment plays a significant role in the development of biomechanical disorders of body posture. According to these factors body posture tests were carried out in a group of 65 students aged 7 years, using the projection moiré method in 4 positions: 1-habitual posture, 2-posture after 10-minute of asymmetric axial load, 3-a posture after one minute of the load removal, 4- a posture after two minutes of the load removal. Physical fitness was measured with the Sekita test. The significance of differences between the 1^st and 2^nd measurements was analyzed to determine the impact of the backpack load and the correlation with physical fitness, and to study its influence on the value of the differences in posture features. In conclusion, carrying school supplies on the back induces significant changes in the value of the features describing the body posture in the frontal plane. It should be assumed that the greater the weight of the container and carrying time and intensity of physical effort is the greater the changes will be. Relatedly, it is not recommended to carry school supplies weighing more than 4 kg by first-grade students. Moreover, physical fitness has a various and sex-dependent influence on the value of changes in body posture features because of carrying school supplies. Among boys it significantly affects the asymmetry of the torso bend, shoulder height, the waist triangles height and width, whereas among girls it affects the asymmetry of the shoulders and the distance of the angles of the lower shoulder blades from the line of the spinous processes of the spine. Among boys the changes in the value of posture features are mostly influenced by endurance and speed, but strength, power and agility are of lower influence, whereas among girls only agility matters.