BackgroundPostural development progresses through a series of stages (growth spurts, development of balance and coordination, postural stability) which occur when children are at school age. The reduction in the level of physical activity, increased body weight, overloaded school bags, asymmetry of the backpack straps, the method of putting on and taking off the backpacks and increased usage of electronic devices have negative side effects such as bad body posture habits.MethodsA prospective cohort study in the group of 155 pupils at early school age 7–9 years old has been conducted. Examinations have been conducted twice: first, at the beginning of the school year (initial examination) and second – after 10–11 months (final examination). Age, gender, BMI, weight of school bag carried to school and the length of straps have been assessed. Body posture measurement (using Adams’ test), the evaluation of the plumb line deflection from the gluteal cleft, the angle values of kyphosis and lordosis (according to Dobosiewicz methodology) and the pelvis and shoulder blades position (using a ruler and pediscoliometer) have been also measured.ResultsThe mean weight of a school bag in the initial study was 6.3 ± 0.8 (range between 4,7 and 9 kg). A tendency to carry slightly heavier school bags was noted in boys (6.7 vs. 5.9 kg; p = 0,00001). This tendency has linearly changed with age (R = 0.68; p < 0,001). In 3.2% of all school bags of children, weights exceeded norms with regard to the weight of the pupil. The increase of torso rotation exceeding norms was observed in 35.3% of girls (mean 2.7 ± 1.2) and in 60.9% of boys (mean 2.3 ± 1.3). The increase of kyphosis angle was noted in 48.5% of girls and in 36.8% of boys. The difference of straps length had a significant influence on the increase of rotation in upper thoracic spine, thoracolumbar junction and it also had influence on the decrease of lumbar lordosis in the group of girls.ConclusionsDifferences in the weight of school bags after one school year have influenced changes in body posture abnormalities, especially in rotation parameters. Backpack straps asymmetry was noticeably stronger in the group of girls and the difference between braces may have an impact on some posturometric parameters. Lack of proper backpack lifting skills tends to create programs and training systems in this regard.

IntroductionApart from many positive changes associated with technical civilization, there are also – from the health point of view – some threats. The reduction in the level of physical activity is one of them. The aim of the study was to investigate whether there are any relationships between children’s physical activity and behaviors, and to assess the impact of the adults’ activity on their children’s habits.Material and methodsThe study involved a group of 340 children aged 7–12 years (mean age: 9.81 ±1.7) and their parents. In order to evaluate children’s physical activity and the amount of time that they spend with electronic devices, an original questionnaire and the IPAQ questionnaire were used.ResultsChildren usually use electronic devices between 2 and 7 days per week (mean: 4.74 ±0.86), regardless of sex (p > 0.09) and spend between 5 and 1620 min per week (mean: 459.46 ±308.1) with their mobile phone, tablet, PCs and TVs. 67.92% of boys and 69.61% of girls lead an active lifestyle. The children’s activity level depends on their parents’ level of activity (p < 0.000001). Parents of semi-active children lead a lifestyle with a moderate level of physical activity.ConclusionsThe level of physical activity in younger children depends on the children’s relationship with their parents and their level of activity. Children spend a lot of free time with their electronic devices. It is necessary to develop and implement activities intended to raise awareness of children and their families about the effects of hypokinesis.