THE IMPACT OF SCHOOL BAG MASS ON CHILD\u27S HEALTH

Mnogi znanstvenici se slažu da je masa torbe jedan od najvažnijih faktora koji može utjecati na zdravlje i pravilan rast djeteta, osobito u osnovnoj školi. Cilj istraživanja je utvrditi utjecaj mase školske torbe na pojavu asimetrije donjih ekstremiteta. Protokolom istraživanja mjerena je okomita sila reakcije podloge Fz pri kontaktu stopala s podlogom pri simuliranim gibanjima u laboratoriju. Za simulaciju su odabrana gibanja koje dijete izvodi spontano u jednom školskom danu. Testovi koji su obuhvatili ova gibanja su: hod po ravnoj površini, hod uz stepenice i hod niz stepenice. Testovi su izvoðeni bez i sa školskom torbom. Za prikupljanje, obradu i analizu signala korišten je BTS, Elite sustav koji sadrži platformu za mjerenje sila reakcije podloge, proizvoðača Kistler. Za testiranje statistički značajne razlike izmeðu ekstremiteta korišten je studentov t-test za zavisne varijable uz pogrešku zakljuèivanja od 0.05 (p<0.05). Kao dešnjakinja, ispitanica dominantno koristi desnu nogu što je vidljivo u povećanoj maksimalnoj vrijednosti sile u testovima „hodu po ravnoj površini“ i „hodu uz stepenice“. Obrnuto, u zahtjevnijem testu „hod niz stepenice“ maksimum sile je manja od maksimuma lijeve strane i pri nošenju torbe i bez nje. Istraživanje ukazuje da aplikacijom vanjskog opterećenja dolazi do pojave asimetrija i razlike izmeðu ekstremiteta koja se vizualizacijom ne može kvantificirati. Osobito je ova razlika izmeðu desne i lijeve noge vidljiva u najzahtjevnijem testu „hod niz stepenice sa torbom“ u kojem su zabilježene četiri razlike koje se protežu kroz sve tri glavne faze hoda. U svakodnevnom životu ove statistički značajne razlike mogu ukazati na deficit mišićne snage, a uz neaktivni način života i umanjenu razinu tjelesne aktivnosti mogu biti potencijalno uzrok nastanka ozljeda kralježnice i lokomotornog sustava djeteta s posljedicama koje će ga pratiti kroz cijeli život.Many scientists agree that the weight of the school bags is one of the most important factors that may affect the health and proper growth of the child, especially in elementary school. The aim of the research is to determine the effect of weight of school bags on the appearance of asymmetry of the lower extremities. Protocol research measured the vertical load Fz ground reaction upon contact with the ground at the foot simulated movements in the laboratory. Motions that child performes spontaneously in one school day were selected for simulation. The tests, involving the following movements, are: walking on a flat surface, walking up the stairs and walking down the stairs. Tests were carried out with and without the bag. For data collection, processing and analysis of signals, BTS was used, Elite system that contains a platform for measuring ground reaction force, manufacturers Kistler. To test statistically significant difference between limbs, Student\u27s t-test for dependent variables with error inference of 0.05 (p <0.05). was used. As a right-handed, subject predominantly uses his right leg which is evident in the increased maximum force values in tests of walking on a flat surface and walking up the stairs. Conversely, in demanding test walking down the stairs maximum force is less than the maximum left, with and without bag. Research indicates that the application of external loads can lead to the asymmetry and differences between limbs, which can not be quantified by visual inspection. In particular, this difference between the right and left legs is visible in the most demanding test of a walk down the stairs with a bag, which recorded four differences that extend through all three main stages walk. In everyday life, these statistically significant differences may indicate a deficit of muscle strength, and with inadequate physical activity and reduced levels of physical activity, may be a potential cause of injury of the spine and musculoskeletal system of the child with the consequences that will follow him throughout life

THE IMPACT OF SCHOOL BAG MASS ON CHILD\u27S HEALTH

Mnogi znanstvenici se slažu da je masa torbe jedan od najvažnijih faktora koji može utjecati na zdravlje i pravilan rast djeteta, osobito u osnovnoj školi. Cilj istraživanja je utvrditi utjecaj mase školske torbe na pojavu asimetrije donjih ekstremiteta. Protokolom istraživanja mjerena je okomita sila reakcije podloge Fz pri kontaktu stopala s podlogom pri simuliranim gibanjima u laboratoriju. Za simulaciju su odabrana gibanja koje dijete izvodi spontano u jednom školskom danu. Testovi koji su obuhvatili ova gibanja su: hod po ravnoj površini, hod uz stepenice i hod niz stepenice. Testovi su izvoðeni bez i sa školskom torbom. Za prikupljanje, obradu i analizu signala korišten je BTS, Elite sustav koji sadrži platformu za mjerenje sila reakcije podloge, proizvoðača Kistler. Za testiranje statistički značajne razlike izmeðu ekstremiteta korišten je studentov t-test za zavisne varijable uz pogrešku zakljuèivanja od 0.05 (p<0.05). Kao dešnjakinja, ispitanica dominantno koristi desnu nogu što je vidljivo u povećanoj maksimalnoj vrijednosti sile u testovima „hodu po ravnoj površini“ i „hodu uz stepenice“. Obrnuto, u zahtjevnijem testu „hod niz stepenice“ maksimum sile je manja od maksimuma lijeve strane i pri nošenju torbe i bez nje. Istraživanje ukazuje da aplikacijom vanjskog opterećenja dolazi do pojave asimetrija i razlike izmeðu ekstremiteta koja se vizualizacijom ne može kvantificirati. Osobito je ova razlika izmeðu desne i lijeve noge vidljiva u najzahtjevnijem testu „hod niz stepenice sa torbom“ u kojem su zabilježene četiri razlike koje se protežu kroz sve tri glavne faze hoda. U svakodnevnom životu ove statistički značajne razlike mogu ukazati na deficit mišićne snage, a uz neaktivni način života i umanjenu razinu tjelesne aktivnosti mogu biti potencijalno uzrok nastanka ozljeda kralježnice i lokomotornog sustava djeteta s posljedicama koje će ga pratiti kroz cijeli život.Many scientists agree that the weight of the school bags is one of the most important factors that may affect the health and proper growth of the child, especially in elementary school. The aim of the research is to determine the effect of weight of school bags on the appearance of asymmetry of the lower extremities. Protocol research measured the vertical load Fz ground reaction upon contact with the ground at the foot simulated movements in the laboratory. Motions that child performes spontaneously in one school day were selected for simulation. The tests, involving the following movements, are: walking on a flat surface, walking up the stairs and walking down the stairs. Tests were carried out with and without the bag. For data collection, processing and analysis of signals, BTS was used, Elite system that contains a platform for measuring ground reaction force, manufacturers Kistler. To test statistically significant difference between limbs, Student\u27s t-test for dependent variables with error inference of 0.05 (p <0.05). was used. As a right-handed, subject predominantly uses his right leg which is evident in the increased maximum force values in tests of walking on a flat surface and walking up the stairs. Conversely, in demanding test walking down the stairs maximum force is less than the maximum left, with and without bag. Research indicates that the application of external loads can lead to the asymmetry and differences between limbs, which can not be quantified by visual inspection. In particular, this difference between the right and left legs is visible in the most demanding test of a walk down the stairs with a bag, which recorded four differences that extend through all three main stages walk. In everyday life, these statistically significant differences may indicate a deficit of muscle strength, and with inadequate physical activity and reduced levels of physical activity, may be a potential cause of injury of the spine and musculoskeletal system of the child with the consequences that will follow him throughout life

How Do Elementary Students in Turkey and the Czech Republic Perceive the Game Concept? A Phenomenographic Study With Draw and Write Technique

The purpose of this study is to compare the perception concerning game concept of 4th grade students in Turkey and the Czech Republic. 19 fourth grade elementary students in the Czech Republic and 40 fourth grade elementary students in Turkey were selected by criterion and convenience sampling. They responded to a specific question "What is the meaning of game for you?" effectively through writing and drawing. Phenomenographic analysis was used to analyze the data. As a result, it is detected that fourth grade elementary students in Turkey and the Czech Republic perceive the game concept as real games more than digital games. Although the two groups have different cultural characteristics they drew and wrote the same games in some main categories. In addition, students in Turkey drew and wrote digital games less frequently than the students in the Czech Republic

NET KNEE JOINT PEAK POWER OUTPUT IN FOUR LANDING STRATEGIES AFTER BLOCK IN VOLLEYBALL

The maximal rate of energy absorption of the knee joint represents a risk factor in noncontact knee injuries. The aim of the study is to compare the absorbed net knee peak power during a bilateral landing after a block in a stick, balance, step back and run back landing strategies. Twelve male professional volleyball players of the highest caliber in the Czech Republic (aged 24.5 ± 4.6 years; height 196.8 ± 0.1 cm; mass 90.1 ± 8.3 kg) participated in this study. From the aspect of the absorbed net knee joint peak power, the landing strategy step back and stick landing appears to be the best option. The balance landing may be in greater risk of non-contact knee injuries

Correlation between relative schoolbag weight and gender and age differences of the schoolchildren in the primary school

Ova studija istraživala je relativnu masu školske torbe i njenu povezanost sa spolno-dobnim razlikama djece školskog uzrasta od prvog do devetog razreda u osnovnim školama grada Brna u Češkoj. Mjerenja morfoloških karakteristika djece i mase školske torbe provedena su u pet različitih škola. U ovoj studiji sudjelovalo je ukupno 584 školske djece, 44,35% djevojčica (N = 259) i 55,65% dječaka (N = 325), prosječne dobi 9,67 (± 2,4) godine i tjelesne mase 37,5 kg (± 13, 4). Srednja masa školske torbe iznosila je 4,93 kg (± 1,32) i predstavljala je 14,0% (± 0,5) srednje tjelesne mase djece. U statističkoj analizi korištenjem faktografske ANOVA, uz statističku značajnost od p ≤ 0.05, uočena je statistički značajna razlika između relativne mase školske torbe prema dobi ispitanika (p = 0,000). Školarci u prva četiri razreda imaju statistički značajnu veću relativnu masu školske torbe u odnosu na njihove starije kolege. S druge strane, ne postoji statistički značajna razlika između relativne mase školske torbe i spola (p = 0,240), ali postoji statistički značajna razlika između relativne mase školske torbe i interakcije između spola i dobi (p = 0,006). Ovo istraživanje je pokazalo da školarci u njihovoj ranoj fazi imaju veće opterećenje školskom torbom što predstavlja veliki faktor rizika tijekom vrlo osjetljive faze njihovog rasta i razvoja.This study investigated relative schoolbag weight and the correlation between relative schoolbag weight and gender and age differences of the schoolchildren in nine grades of primary schools in Brno, Czech Republic. Measurements of children’s anthropometry and schoolbag weight were taken in five different schools. In total 584 school children, 44,35 % girls (N = 259) and 55,65 % boys (N = 325), mean age 9,67 (± 2,4) years and body weight 37,5 kg (± 13,4) took part in this study. Mean schoolbag weight was 4,93 kg (± 1,32) and it represented 14,0 % (± 0,5) of children’s body weight. By using a factorial ANOVA in statistical analysis and by setting the statistical significance at p ≤ 0,05, the statistically significant difference between the relative schoolbag weight by ages of participants was noticed (p = 0,000). Schoolchildren in first four grades have statistically significant higher relative schoolbag weight than their older colleagues. On the other hand, there’s no statistically significant difference between the relative schoolbag weight and the gender (p = 0,240), but there is a statistically significant difference between the relative schoolbag weight and the interaction between gender and age (p = 0,006). This study showed that for schoolchildren in their early stage of growth, schoolbag load is bigger, and it represents a big risk factor during the very sensitive stage of their growth and development

Analysis of ground reaction force in gait during different phases of pregnancy

During pregnancy there are increased biomechanical demands on women affecting gait parameters. The purpose of this study was to analyze changes in vertical ground reaction force (GRF), normalized by body mass, during advancing phases of pregnancy. Nine pregnant subjects participated in this study at three pregnancy stages. To determine in-shoe pressure distribution Pedar Insole System was used (100 Hz). Analysis was done on 200 steps cycles of treadmill walking at the velocity of 0.83 m·s-1. To compare the differences of GRFs in maximal weight acceptance, middle stance and push-off phase and time to reach these forces among three pregnancy stages, repeated-measures ANOVA was performed to obtain partial eta-squared values to measure the effect size (η>.10). To interpret the overall mean differences between the three pregnancy stages Cohen’s d was applied (d>.20). Altered gait pattern during advancing phases of pregnancy demonstrated in the current study by a significant decrease in force of maximal weight acceptance and an increase in main time variables of the step is suggested to be a protective mechanism against overloading the contact area of the foot despite the increase in body mass

Određivanje spolno i dobno specifičnih percentilnih krivulja za neke aspekte fizičke sposobnosti kod adolescenata grada Zagreba

The main purpose of the present study was to develop smoothed percentile curves for physical fitness in adolescents aged 15-18 years from the City of Zagreb. In this cross-sectional study, we recruited 1036 secondary-school students aged 15-18 from eleven randomly selected schools (55.3% of girls). As part of physical fitness, we chose 1-minute sit-ups (#), standing long jump (cm) and sit-and-reach (cm) tests using standardized measuring protocol. The sex- and age-specific smoothed percentile curves with 5th, 10th, 25th, 50th, 75th, 90th and 95th percentile for each physical fitness test were calculated using Lambda-Mu-Sigma method. The 50th percentile for 1-minute sit-ups was between 55 and 58 cm in boys, and between 45 and 47.5 cm in girls. For standing long jump, 50th percentile was between 210 and 215 cm in boys and roughly the same (170 cm) in girls. Finally, 50th percentile for sit-and-reach test was between 60 and 65 cm in boys and between 67.5 and 73 cm in girls. This study aimed to establish physical fitness percentile curves for adolescents from the City of Zagreb. Our reference curves might be used to detect adolescents who are at an extreme risk of having ‘low’ physical fitness status and to implement school-based interventions for physical fitness level enhancement.Glavni cilj ove studije bio je napraviti percentilne krivulje tjelesne spremnosti u adolescenata u dobi od 15 do 18 godina u Gradu Zagrebu. U ovoj poprečno-presječnoj studiji sudjelovalo je 1036-ero srednjoškolaca u dobi od 15 do 18 godina, izabrani slučajnim odabirom iz 11 škola (55,3% djevojaka). Kao dio tjelesne spremnosti izabrali smo podizanje trupa u 1. minuti (broj ponavljanja), skok udalj s mjesta (cm) i test dohvata (cm). Spolno dobne percentilne krivulje sa 5, 10, 25, 50, 75, 90 i 95 percentilom su napravljene služeći se Lambda, Mu i Sigma metodom. Pedeseti percentil za podizanje trupa u 1. minuti je bio između 55 i 58 ponavljanja u dječaka, dok je kod djevojaka bio 45 do 47.5. Za skok udalj s mjesta 50 percentil nalazio se u vrijednosti između 210 i 215 cm kod dječaka i oko 170 cm kod djevojčica. Konačno, 50 percentil kod testa dohvata bio je između 60 i 65 cm kod dječaka i 67,5 i 73 cm kod djevojčica. Ova studija utvrđuje dobno spolne percentile krivulje tjelesne spremnosti kod adolescenata u Gradu Zagrebu. Naše referentne krivulje mogle bi poslužiti u otkrivanju onih adolescenata s povećanim rizikom od „niske” razine tjelesne spremnosti i u implementaciji školskih intervencija koje povećavaju razinu tjelesne spremnosti

Biomehanicki pokazatelji razlika tehnika skok šuta u modernoj košarkaškoj igri

Glavni cilj ovog istraživanja bio je utvrditi dali postoje razlike u izvodenju košarkaškog skok-šuta nakon kretnja i dodane lopte koristeci pritom dvije razlicite tehnike zaustavljanja, jednokontaktnog i dvokontaktnog. U istraživanju je sudjelovao ispitanik clan nacionalne selekcije Hrvatske. Istraživanje je ukljucivale sljedece parametre: vrijeme šuta, najmanja vrijednost centra težišta tijela, najveca vrijednost centra težišta tijela, vrijeme dolaska u najmanju vrijednost centra težišta tijela, prosjecna brzina centra težišta tijela od najmanje do najvece vrijednosti, vrijeme od najmanje do najvece vrijednosti centra težišta tijela, prijedena udaljenost centra težišta tijela horizontalno. Ispitanik je sniman sa šest kamera. Snimke skok šuta obradene su pomocu programskog paketa SIMI Motion, a dobiveni podaci paketom Statistica za Windows. Rezultati su pokazali da postoji statisticki znacajna razlika u tehnikama zaustavljanja kod košarkaškog skok-šuta u najmanjoj vrijednosti centra težišta tijela, najveca vrijednost centra težišta tijela, vrijeme dolaska u najmanju vrijednost centra težišta tijela, vrijeme postizanja najmanje do najvece vrijednosti centra težišta tijela i prijedena udaljenost centra težišta tijela horizontalno. Takoder analizom dobivenih rezultata dolazi se do zakljucka da ne postoje statisticki znacajne razlike u vremenu potrebnom za izvedbu šuta i prosjecnoj brzini centra težišta tijela od najmanje do najvece vrijednosti

Influence of schoolbag carriage on pattern changes in plantar pressure during walking among first-grade schoolchildren

The aim of this study was to determine the influence of schoolbag carriage on pattern changes in plantar pressure during walking among schoolchildren of first grade. The sample consisted of 127 schoolchildren, 48.8% male (n = 62) and 51.2% female (n = 65), aged 6.7 (±0.5) years. The mean schoolbag weight was 4.2 kg (±0.7), which represented 16.9% (±3.9) of children’s body weight, thus exceeding the upper limit of the recommended 15% of the body weight and generally affecting their posture. The study has shown the statistically significant influence of the schoolbag on changes in plantar pressure pattern when walking in relation to walking without the schoolbag. Using a t-test for large dependent samples and by setting statistical significance at p≤.05, the significant increase was noticed in peak pressure for the forefoot (p=.000; 17.1%), midfoot (p=.000; 5.7%) and hindfoot (p=.004; 3.9%) as well as in average pressure for the midfoot (p=.005; 6.2%). Also, due to the compensatory mechanisms activated while the bag was being carried, the statistically significant increase in the contact surface at the forefoot (p=.000; 3.6%) and midfoot (p=.000, 8.8%) occurred. Changes in the distribution of pressure between different parts of the foot are a source of potential foot problems which is why the results of this study have a high applicability in the prevention of foot pathology in the future