WALKING PATTERN ANALYSIS OF PRIMARY SCHOOL CHILDREN DURING LOAD CARRIAGES ON TREADMILL 492

Abstract

The effect of carrying school bags on children was investigated so as to supply a picture of recommended weight of school bag and prevent vertebral problems. Two dimensional video filming and heart rate measurement were carried out in 10 male students of Primary Six (average 11.6 years) during walking on a treadmill with backpack of 0%, 10%, 15%, and 20% of body weight respectively. The body height and weight of the subjects were 149.95 ± 5.55 cm and 44.45 ± 11.41 kg respectively. The subjects were requested to walk at a speed of 1.1m/s for 15 minutes on a treadmill, at each condition of carrying. Loads were put inside the backpack placed on the mid back of the subject. 0% body weight was used as a control for carrying. Video tapes were then digitized and analyzed on Peak Motion Measurement System. Results showed no statistically significant difference between different load conditions in stride length, stride rate, double leg support time, swing time and center of gravity height as well as in heart rate. It was found there was significant difference in single leg support time among different load condition. The F-ratio was F(3.36)=3.461, P<0.05. One-way Scheffe Test indicated that there was significant difference in single leg support time only at between 0% and 20% body weight load conditions. Significant difference was found in inclination of trunk between 0% and the other three load conditions. The F-ratio was F(3.36)=11.64, p<0.01, showing there were significant differences in inclination of trunk between 0% and the other three load conditions. The study could not provide any support to the recommendation of 10% body weight as the guideline for carrying school bag among children. It was also found that heart rate could not be used as the only physiological testing parameter of carrying school bag on children. It was suggested that longitudinal study and the study with EMG testing should be carried out in order to provide information on the causes of vertebral problems related to the load of school bags.