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

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. 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). 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. 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. Le but de cette étude est d’étudier les effets de l’augmentation de la masse corporelle sur la performance de l’équilibre dynamique (LQYBT) et la force musculaire isométrique (pic de couple de force) chez des écoliers de poids normal (HW), en surpoids (OW) et obèses (O). Étude transversale. Parmi les participants figuraient 51 écoliers de 12 à 15 ans du complexe éducatif King Saud – The Middle School, Riyadh. La stabilité dynamique a été analysée avec le test Balance Y pour les membres inférieurs (LQYBT) et la force musculaire isométrique des extenseurs et des fléchisseurs du genou par dynamométrie manuelle (HHD). Les scores d’équilibre dynamique des enfants HW, dans la direction antérieure droite (AT), étaient significativement différents de ceux des enfants OW et O (p=0,010), mais aucune différence n’a été constatée entre les enfants OW et O. Des différences significatives ont été mises en évidence dans la force des muscles extenseurs et fléchisseurs des deux membres chez l