RESUMO
BACKGROUND:The current studies concerning the effect of obesity on children are limited to metabolic physiology, and there is little evidence available on skeletal muscle and motor ability. OBJECTIVE:To compare isokinetic knee muscle strength between obese children and normal children, and analyze the causes of physical performance decline in obese children. METHODS:A total of 56 children were recruited in this study, including 28 obese children and 28 normal children. The isokinetic muscle strength was tested by CON-TREX. The gaits were tested by VICON. The statistical analysis of al the differences between obese children and normal children were measured using SPSS 19.0 software. RESULTS AND CONCLUSION:At the same gait speed, obese children had higher absolute peak torque and average power than normal children (P0.05) except extensor group at 60(°)/s was significantly lower than normal children. At the same gait speed, the torque and power of extensor group were significantly higher than that of flexor group in the two groups (P<0.05);he obese children showed significant differences in the absolute peak torque and absolute average power compared with relative peak torque and relative average power of flexor group at 120(°)/s (P<0.05). In the two groups, the extensor exhibited higher torque in high speed, while the high flexor torque was found in low speed. Normal children had faster cadence and walking speed, significantly smal er step width and shorter stride time than obese children (P<0.05). Obese children have smal er relative strength and higher absolute strength than normal children;in addition, the low cadence and walking speed are found in obese children. These factors contribute to weak limb strength and insufficient motor ability.