Furniture dimensions and postural overload for schoolchildren's head, upper back and upper limbs

The aim of this study was to evaluate how the fixed furniture dimensions match with students' anthropometry and to describe head, upper back and upper limbs postures and movements. Evaluation was performed in 48 students from a Brazilian state school. Furniture dimensions were measured with metric tape, movements and postures by inclinometers (Logger Tecknologi, ?karp, Sweden). Seat height was high for 21% and low for 36% of the students; seat length was short for 45% and long for 9% and table height was high for 53% and low for 28%. Regression analysis showed that seat/popliteal height quotient is explained by 90th percentile of upper back inclination (β=0.410) and 90th percentile of right upper arm elevation (β=-0.293). For seat/thigh length quotient the significant variables were 90th percentile of upper back velocity (β=-0.282) and 90th percentile of right upper arm elevation (β=0.410). This study showed a relationship between furniture mismatch and postural overload. When the seat height is low students increase upper back left inclination and right upper arm elevation; when the seat is short students decrease the upper back flexion velocity and increase right upper arm elevation.     

Effects of a school based exercise program on children's resistance and flexibility

The aim of this study was to evaluate the short term effects of an exercise program on abdominal and back muscles resistance and hamstring flexibility among schoolchildren. Fifty eight healthy schoolchildren were divided into two groups: experimental (15 males and 14 females; mean age 12.2(1.8 years) and control (14 males and 15 females; mean age 11.9(2.1 years). The intervention was performed twice a week, on nonconsecutive days, during six weeks. The duration of each session was fifty minutes and they were composed by warming up aerobic exercises, isotonic and isometric abdominal and back muscle exercises and hamstring stretching. The intervention effects were evaluated through Kraus-Weber test (abdominal resistance), modified Biering-S?rensen test (back muscle resistance) and sit and reach test (hamstring flexibility). Data were analyzed by mixed-design two-way ANOVA, with one between-subjects and one within-subject (time) factors. The alpha level was set at P≤0.05. The experimental group improved back muscles resistance and hamstring flexibility, but not abdominal muscles resistance. There was a significant interaction between groups and time for back muscles resistance (P=0.018) and for hamstring flexibility (P=0.017). The 6-week training period showed positive results in improving back muscles resistance and hamstring flexibility of schoolchildren.