The role of body mass index on dynamic balance and muscle strength in Saudi schoolchildren

Objectives. - The aim of this study is to investigate the effects of increased body mass on the performance of the dynamic balance (LQYBT) and isometric muscle strength (peak torque) in healthy weight (HW), overweight (OW), and obese (O) schoolchildren. Equipment and methods. - Cross sectional design. Participants included 51 male schoolchildren, aged 12 to 15 years from King Saud educational complex-The Middle School, Riyadh. Dynamic balance was analyzed by Lower quarter Y balance test (LQYBT) and isometric muscle strength of knee extensors and flexors with Handheld Dynamometry (HHD). Results. -The dynamic balance scores of HW children, in the right anterior (AT) direction, were significantly different from OW and O children (P= 0.010), but no differences were found between O and OW children. Significant differences were shown in the strength of the extensor and flexor muscles of both limbs in HW, OW, and O children (extensors left: F=11.853, right: F= 7.660; P=0.001; flexors left: F= 16.417, right: F= 4.576; P=0.001). Knee extensors and flexors in the HW group were significantly positively correlated with the reach scores of right AT direction, but none with the other directions. There was a significant positive correlation between BMI and Hamstring strength, while this correlation is far less obvious with the quadriceps. Conclusions. - The findings imply that increased BMI reduces balance ability in anterior reach direction (LQYBT) and none in other directions. The isometric strength of obese children was different from the healthy weight children. (C) 2020 Elsevier Masson SAS. All rights reserved.