الفهرس 
Title : Anticipatory postural adjustement associated with upper extrimity movements while standing in normal children
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Abstract
Objective: Anticipatory postural adjustments (APAs) play an important role in the performance of many activities requiring the maintenance of vertical posture. However, little is known about how children utilize APAs during self-induced postural perturbations. Any perturbation in the body such as a fast arm or leg movements endangers the body Methods: One hundred normally developed children participated in this study, their age ranged from 7-12 years old. They were divided normally into three aged groups, group A, ranged in age from 7-9 years, group B, ranged in age from 9-11 years and group C, ranged in age from 11-12 years. They were analyzed by EMG during performing unilateral shoulder flexion, the electromyography (EMG) activities of dorsal and ventral trunk and lower limbs muscles were recorded to measure the anticipatory activation of postural muscles (dorsal and ventral trunk and lower limbs muscles) before voluntary arm movement while standing. Results: in all three groups the anticipatory changes in EMG route mean square amplitude, mean amplitude and peak amplitude were higher in the dorsal trunk muscles (ES) on the epsilateral side than in contralateral side and the activity of dorsal leg muscles which were higher in magnitude than the activity of the ventral leg muscles restricting forward movement of the body and preserving balance. It also showed that, the activation of postural trunk and upper leg muscles occurred before burst onset activation of AD in all three groups: the dorsal muscles of the trunk (RES, LES), and then the dorsal muscle of thigh (BF) and followed a proximal to distal order of activation