The Role of Birth Order and Birth Weight in the Balance of Boys Aged 9-11 Years Old

Motor skills are always considered as one of the effective factors on human activities. The purpose of this research is to study the role of birth order and birth weight in the static and dynamic balance of boys aged 9 -11 years old. 94 male students have been evaluated in this research. The personal information questionnaire and medical records were used to acquire data pertaining to birth order and birth weight. Also, parts of Lincoln -Oseretsky test pertaining to balance were used to evaluate static and dynamic balance. The results indicated that second children and children with normal weight had higher average scores rather than first children, onl y children, and children with low and high weight in most items of static and dynamic balance (p < 0.01). The superiority of second children over other children is probably because of the existence of older siblings which younger ones follow as models in f amilies.