human body posture is subject to change (1-4). This is mostly visible during the period of growth and development of children. Rapid changes of the environment, sedentary style of life, limitations in physical activity and inadequate eating habits are inseparable from the civilization progress (5-8). In spite of ORIGINALNI NAUČNI ČLANAK

Introduction: Carrying a school bag is a dominant activity that a child performs during daily productive activities. The aim of the research is to examine how carrying a school bag of different weights affects the distribution of force and plantar pressure during normal walking on the flat terrain of children of varying levels of physical activity.Methods: The pilot study included 124 students aged 11-12 from Banja Luka. According to the protocol, each group of respondents was treated with an intervention-customized school bag and a comparator-school bag that the child only opted for. For the research, the Physical Activity Questionnaire for Older Children, measurement of anthropometric parameters, school bag weight, and Zebris tape (Zebris Medical GmbH, Germany) were used for gait analysis.Results: Inactive children achieved the lowest and active children’s highest walking speed during normal walking without a bag, with their customized school bag. When carrying a custom school bag: The highest maximum force is projected on the left heel 330.72 N in inactive children, and the lowest 265.93 N in moderately active children, the highest maximum pressure on the left heel is registered in inactive children, 27.60 N/cm2, and the lowest 21.85 N/cm2 in moderately active children. The maximum force-time of % of standing time on the left foot in the middle part lasted the longest in inactive children, and the shortest active children carried their school bag 40.31% and a custom school bag 39.76%.Conclusion: High physical activity and individual adjustment to distribute the burden well allow the child to adequately respond to the loads carried by the weight of the school bag.

Saţetak.Pravilno držanje tijela je pokazatelj dobrog zdravlja, pravilnog rasta i razvoja, zbog čega je važno da učenje držanja tijela počne od najranijeg uzrasta primjenom različitih oblika fizičke aktivnosti. Cilj istraživanja je ispitati uticaj aspekata fizičke aktivnosti na komponente držanja tijela djece školskog uzrasta. Istraživanje je obuhvatilo 120 ispitanika uzrasta od 10 do 16 godina grupisanih u tri grupe, u kojima je statifikovan jednak broj dječaka i djevojčica. Prvu grupu čini 40 djece koja se aktivno bave sportom. Drugu grupu čini 40 djece koja se aktivno ne bave sportom, a treću grupu 40 djece koja imaju deformitet kičmenog stuba. Za potrebe istraživanja koristili smo: test za procjenu stepena fizičke aktivnosti i test za ocjenu držanja tijela. Primjenom multiple regresione analize utvrdili smo da postoji uticaj različitih prediktora na zavisne varijable za sva tri kategorički definisana uzorka. Najjača pozitivna veza ustanovljena je kod prvog kategorički definisanog uzorka između prediktora vježbe zagrijavanja na treningu i položaj držanja nogu, i visina veze iznosi β = 0,43. Najjača negativna veza ustanovljena je, takođe, kod prvog kategorički definisanog uzorka između prediktora vrijeme provedeno za kompjuterom i položaj držanja nogu, i visina veze iznosi β=-0,35. Ustanovljeno je da postoji razlika u stepenu fizičke aktivnosti (F=95,687 i p= 0,01) i razlika u držanju tijela (F=10,93 i p=0,01) između tri kategorički definisana uzorka. Rezultati ukazuju na neophodnost promocije raznih oblika fizičke aktivnosti djece školskog uzrasta u cilju njihovog pravilnog rasta i razvoja.Ključne reči: razvoj djece, držanje tijela, fizička aktivnost. UvodPravilno drţanje tijela predstavlja poloţaj tijela u vertikalnom i ravnoteţnom poloţaju u odnosu na ravan na kojoj se ljudsko tijelo zadrţava ili kreće, sa pravilno rasporeĊenim dijelovima tijela ĉijim se ispravnim drţanjem stvara otpor sili zemljine teţe, te se tijelo istovremeno moţe zadrţati ili kretati u vertikalnom poloţaju i pri tome odrţavati i stimulisati sve fiziološke procese u organizmu (Bjeković i sar., 2011). U svakoj ţivotnoj dobi prisutno je više tipova drţanja tijela, do ĉijeg oblikovanja dolazi usljed mnogobrojnih uticaja kretnje aktivnosti ĉovjeka (Opavski, 1998). Ĉinjenicu da se djeĉiji organizam relativno lako mijenja pod uticajem okoline treba prihvatiti kao realnost, istovremeno je koristeći u radu sa djecom radi podsticanja njihovog rasta i razvoja. Rast i razvoj djeteta zavisi od adekvatne stimulacije, ĉiji je najvaţniji faktor pokret. Od najranijeg uzrasta djeca treba da usvajaju zdrave ţivotne navike, kako bi organizam na fiziĉke napore imao sposobnost brze adaptacije, kao i sposobnost brzog oporavka poslije napornog rada. Fiziĉka aktivnost nije samo potreba za odreĊenim mehaniĉkim radnjama vaţnim za opstanak jedinke, nego je istovremeno Autor za korespondenciju: Dijana Laštro,

Background/Aim: A school bag is a device whose purpose is to store things that are necessary for a child in performing daily productive activities. The aim of the research was to examine how much parents are informed about the school bag and which specifications are crucial when choosing a school bag for their children. Material and methods: The prospective study included 150 parents of students aged 11 to 12 from Banja Luka. For the purposes of the research, a questionnaire with closed and open questions was used. Results: More than 97 % of the surveyed parents belonged to the age range of 30 to 49 years. The largest number of surveyed parents have had secondary education 44 %, but the number of university-educated parents was also very high 39.3 %. Ninety-six percent of students used a backpack. School bags in 97.4 % of cases were purchased in stores. Only in 10 % of cases, school bags fully meet the basic criteria. In the remaining 90 % of cases, there was an absence of at least one or more desired characteristics. Using the Chi-squared test (ch2 = 245.45; p < 0.001), a significant difference between the desired and the achieved result was statistically proven. 77.3 % of parents did not receive information about the school bag. Salespeople (11.3 %), other parents and friends (9.3 %) were the main source of information before purchasing a school bag. In the future, 54 % of parents would like to get information about the school bag through lectures and practical workshops for children and parents. Conclusion: Greater information enables adequate selection and reduces the possibility of marketing tricks and influences on consumers when choosing the desired product such as a school bag. Parents have an important role to play in ensuring unhindered growth and development during the educational process and in raising children's awareness and supervision of the proper use of the school bag.