04 April 2026 : Clinical Research
Effect of School Backpack Weight on Shape of Children's Feet
Sabina Lizis
ABCDEF 1, Justyna Leszczak ADEF 1, Ewa Puszczałowska-Lizis ADEF 1*
DOI: 10.12659/MSM.952039
Med Sci Monit 2026; 32:e952039
Table 7 Relationships between values for school backpack weight in relation to body mass and values for differences in individual foot characteristics measured at first and second examination.
| Difference in foot characteristics (first examination – second examination) | Weight of the school backpack in relation to the child’s body mass [%] | |||
|---|---|---|---|---|
| Girls | Boys | |||
| r/R | P | R | P | |
| Foot length of the right foot [cm] | r=0.04 | 0.763 | R=0.02 | 0.873 |
| Foot length of the left foot [cm] | r=0.11 | 0.401 | R=−0.07 | 0.597 |
| Foot width of the right foot [cm] | r=0.34 | 0.008* | R=0.10 | 0.475 |
| Foot width of the left foot [cm] | r=0.41 | 0.001* | R=0.12 | 0.369 |
| Clarke’s angle of the right foot [°] | R=−0.70 | <0.001* | R=−0.56 | <0.001* |
| Clarke’s angle of the left foot [°] | R=−0.75 | <0.001* | R=−0.62 | <0.001* |
| Heel angle γ of the right foot [°] | R=0.34 | 0.007* | R=0.22 | 0.091 |
| Heel angle γ of the left foot [°] | R=0.39 | 0.002* | R=0.24 | 0.070 |
| Hallux valgus angle α of the right foot [°] | r=−0.09 | 0.452 | R=0.25 | 0.060 |
| Hallux valgus angle α of the left foot [°] | R=0.30 | 0.017* | R=0.16 | 0.245 |
| Angle of the varus deformity of the fifth toe β of the right foot [°] | r=0.13 | 0.312 | R=0.13 | 0.315 |
| Angle of the varus deformity of the fifth toe β of the right foot [°] | r=0.09 | 0.477 | R=0.13 | 0.330 |
| r – Pearson’s correlation coefficient; R – Spearman’s rank correlation coefficient; – probability value. * | ||||