An approach to establishing the thresholds of plantar loading in obese children

Abstract

Excessive weight-bearing positively affects the overloaded foot, which can induce multiple foot deformities [1]. Previous studies normalized maximum force to eliminate the influence of body weight on the mechanical loading of the foot [2]. To explore body weight itself to the change of the plantar pressure distribution, this study adopts a strategy of body weight scale to compare loading patterns between normal-weighted and obese children. It can acquire the exceeded foot loading data accurately for obese children compared to normal-weighted children, which could lead to finding the pressure threshold in obese children. Is there a method to grade the pressure thresholds of plantar overload in obese children? A cross-sectional study with a large sample size of 1170 participants aged 7-11 years was used to divide normal-weighted (n = 812) and obese children (n = 358) into eight groups based on the same weight class strategy: group 1 (25.5-30.4 kg), group 2 (30.5-35.4 kg), group 3 (35.5-40.4 kg), group 4 (40.5-45.4 kg), group 5 (45.5-50.4 kg), group 6 (50.5-55.4 kg), group 7 (55.5-60.4 kg), group 8 (60.5-65.4 kg). Dynamic plantar pressure data were collected using a Footscan® plantar pressure system (RSscan International, Belgium). Maximum forces were extracted from the main plantar region using principal component analysis. The change of obese children with the same weight grade compared with normal-weighted children was divided into six grades, to define the pressure threshold of obese children's plantar pressure compared with normal-weighted children. The assessment criteria of the pressure threshold level are set at 10 N (trivial effect), 10-20 N (very weak effect), 20-30 N (weak effect), 30-40 N (moderate effect), 40-50 N (strong effect) and 50-60 N (very strong effect). Table 1 shows the levels of the pressure threshold in obese children compared to normal-weighted children with the same weight class.Download : Download high-res image (64KB)Download : Download full-size image The results showed that the maximum force of obese children with 25.5-35.4 kg did not cause significant damage to the main stress area of the plantar, and there was no need for clinical intervention or other related foot decompression strategies. When the weight of obese children is greater than 35.5 kg, it is necessary to pay attention to the influence of excessive foot load on the development and health of obese children's feet. This study can provide data support for foot decompression protocols such as shoes or insoles and weight loss training.