Biomechanical Analysis of Obese and Non-Obese Children During the Gait

This study examined the effects of obesity on dynamic plantar pressure distributions in children. Experimental data on body mass index (BMI) and plantar pressures were collected for 15 obese children and 15 non-obese children. 15 obese (age 9.8±2.0 y, BMI 25.8±3.8 kg/m ) children matched to 15 non-obese children (age 9.9±2.1 y, BMI 16.8±2.0 kg/m 2 ), for age, weight, and height. Right, and left foot plantar pressures were obtained using a Foot scan platform, and foot scan software is used for plantar pressure measurements to calculate the peak force and pressure experienced under the area of each child’s feet during dynamic conditions. These variables were measured under ten regions of interest in each footprint: Lateral heel, Medial heel, Mid-foot, Metatarsal 5, Metatarsal 4, Metatarsal 3, Metatarsal 2, Metatarsal 1, Toes 2-5, Toe1. Descriptive statistics and one-way analysis with stepwise were used to analyze the data. While walking, the obese children generated significantly higher forces over all areas of their feet, except the toes. Despite

This study examined the effects of obesity on dynamic plantar pressure distributions in children. Experimental data on body mass index (BMI) and plantar pressures were collected for 15 obese children and 15 non-obese children. 15 obese (age 9.8±2.0 y, BMI 25.8±3.8 kg/m 2 ) children matched to 15 non-obese children (age 9.9±2.1 y, BMI 16.8±2.0 kg/m 2 ), for age, weight, and height. Right, and left foot plantar pressures were obtained using a Foot scan platform, and foot scan software is used for plantar pressure measurements to calculate the peak force and pressure experienced under the area of each child's feet during dynamic conditions. These variables were measured under ten regions of interest in each footprint: Lateral heel, Medial heel, Mid-foot, Metatarsal 5, Metatarsal 4, Metatarsal 3, Metatarsal 2, Metatarsal 1, Toes 2-5, Toe1. Descriptive statistics and one-way analysis with stepwise were used to analyze the data. While walking, the obese children generated significantly higher forces over all areas of their feet, except the toes. Despite distributing these higher forces over a significantly larger foot area when walking, the obese children experienced significantly higher plantar pressures in the mid-foot and under the second to fifth metatarsal heads compared to the non-obese children. The greatest effect of body weight on higher peak pressure in the obese children was found under the longitudinal arch of the foot and the metatarsal.

Statistical Analysis
Means (SD) were calculated for different time and force variables. The differences within the groups and between the groups were compared using a one-way analysis of variance.
Differences of p<0.05 were considered significant.

Result
There was a significant delay to the time of peak Pressure under lateral forefoot (Meta5, Meta4, Meta3), and toes in the obese children (  Table 2 represents the comparison between the two groups during gait.

Discussion
The increased dynamic forces that generated from heel to forefoot were as expected in obese children. But the increased body mass did not affect the toes region (Toe1-5 Obese children in the present study generated significantly higher mean peak pressures under the mid-foot and third to fifth metatarsal heads, compared to their non-obese counterparts.
Because obese children have flatter feet this cause increasing in the mid-foot pressure. The mid-foot region contacts the pressure platform, generating pressure data on this foot area. The peak pressures generated by the obese children for Metatarsal 3, Metatarsal 4, and Metatarsal 5 were high relative to other foot regions, as well as being significantly higher than the plantar pressures generated by the non-obese children. As these higher pressures are being experienced on smaller bony and ligamentous structures surrounding the second to fifth metatarsal heads, this may have negative consequences for the feet of obese child in terms of an increased risk of forefoot pathologies.

Conclusion
Based on the findings of the present study, it is postulated that obese children might be at an increased risk of developing foot discomfort and/or foot pathologies, such as stress fractures in the forefoot. It is recommended that the effects of obesity on the structural and functional characteristics of children's feet be further investigated.