Podiatric and Stabilographic Examinations of the Effects of School Bag Carrying in Children Aged 11 to 15 Years

Background: The issues raised in this study were inspired by the concern for the musculoskeletal status of school children. Carrying excess weight in the form of a school bag in this period of life affects the correct body posture of school children. The aim of the study was to analyze the influence of school bags on the feet force distribution on the ground and postural balance in children of both sexes between 11 and 15 years of age. Methods: The study investigated the distribution of pressure forces on the sole of the foot and its arch. The center of pressure for both feet and the whole body was also examined. The participants were 100 students from primary schools in Gdańsk, aged 11 to 15, including 54 girls and 46 boys. The research used a podobarographic platform that measures the distribution of foot pressure to the ground. The examinations included two measurements: in the first, the children stood on the platform in a natural position. Then, a 5 kg backpack was put on and they stood on the platform again. Results: Statistically significant differences were found in the distribution of the foot pressure on the ground in the left metatarsus (p = 0.000) and heel (p = 0.000) after putting on the backpack in both girls and boys. However, in the right foot, these differences concerned the metatarsal area (p = 0.001). The results of the balance tests were only statistically significant in the group of girls in the right foot sway area (p = 0.020). Conclusions: The school backpack load led to an increase in the values of the heel and metatarsal area measured in the students, causing its flattening.

Effect of Backpack Load Influencing the Cardio-Respiratory Changes in Stair Climbing in Adolescents

Postural and physiological changes are the distinct changes occurring in the adolescence which contributes fitness level of a child. The biomechanics of these children are highly affected by load carriage while climbing stairs which results in increase in cardio respiratory responses. Evaluation of the cardio respiratory changes is necessary in curbing further damage. In the study we evaluated the effect of backpack load influencing the cardio respiratory measures in stair climbing adolescents. 100 adolescents subjects aged 13-16 yrs were selected for the study, with graded loading for three consecutive days. Heart rate, rate of perceived exertion and respiratory rate were measured pre and post loading. Values of all the parameters on each day were compared. With increase in load, increase in heart rate, rate of perceived exertion and respiratory rate were significant when compared with progression in load. Although the measure which is highly affected amongst these was heart rate. The backpack with 30% load produces the elevation of variables at a greater extent hence there should be curbing of weight of 30% of adolescent’s body weight. Key words: Adolescence, Backpack load, Rate of Perceived Exertion.

Stable and Unstable Load Carriage Effects on the Postural Control of Older Adults

The aim of this study was to investigate the effects of backpack load carriage on quiet standing postural control and limits of stability (LOS) of older adults. Fourteen older adults (65 [6] y) performed quiet standing and a forward, right, and left LOS test in 3 conditions, unloaded, stable, and unstable backpack loads while activity of 4 leg muscles was recorded. Stable and unstable loads decreased postural sway (main effect , stable P < .001, unstable P < .001), mediolateral (main effect , stable P = .002, unstable P = .018) and anterior–posterior (main effect , stable P < .001, unstable P = .001) fractal dimension, and LOS distance (main effect , stable P = .011, unstable P = .046) compared with unloaded. Rectus femoris (main effect , stable P = .001, unstable P = .010) and gastrocnemius (main effect , unstable P = .027) activity increased in loaded conditions during LOS and quiet standing. Gastrocnemius–tibialis anterior coactivation was greater in unstable load than stable loaded quiet standing (main effect , P = .040). These findings suggest older adults adopt conservative postural control strategies minimizing the need for postural corrections in loaded conditions. Reduced LOS may also increase fall risk when carrying a load. However, there was no difference between unstable and stable loads for postural control variables.