Reliability of Functional Balance Tests and Their Correlation With Selected Anthropometric Parameters in Children Aged 7-10 Years

* Corresponding Author: Mahboobeh Dehnavi, MSc. Address: Department of Sports Biomechanics, Faculty of Physical Education and Sports Science, Central Tehran Branch, Islamic Azad University, Tehran, Iran. Tel: +98 (935) 3954320 E-mail: mahboobeh.dehnavi@gmail.com 1. Department of Sports Biomechanics, Faculty of Physical Education and Sports Science, Central Tehran Branch, Islamic Azad University, Tehran, Iran. *Mahboobeh Dehnavi1 , Heidar Sadeghi1, Mehdi Taghva1


Introduction
osture control involves controlling the position of the body in space for two purposes: stability and body orientation. The orientation component is defined as the ability to maintain communication between different parts of the body and also between the body and the environment to perform a specific task [1]. The sta-P bility component referred to static balance, which defines the ability to maintain the center of gravity within the base of support [2] which is effective in performing many daily activities; it has been found that daily activities require certain levels of balance [3]. One of the key factors in assessing the development of children's motor skills is balance assessment [2].
Many balance tests are used to differentiate between healthy children and children with developmental disorders. According to the results of these tests, specialists inter-pret, compare and make decisions about the development of children's motor skills and subsequently adopt the necessary therapeutic and training interventions [4]. Therefore, these balance tests must be reliable and accurate, because the decisions that are made for children based on the results of these balance tests are crucial. Hence, we should identify valid and appropriate tests for this group. In this regard, this study aimed to evaluate the reliability of selected functional balance tests in children aged 7-10 years, and the relationship between these functional balance tests and selected anthropometric parameters to determine the role of anthropometric parameters on the balance of this age group.

Methods
This is a descriptive/correlational study. The study population consisted of all male and female students aged 7-10 years in Sama Elementary School located in Neishabour, Iran. Using cluster sampling method, 80 students (40 girls and 40 boys) were selected as the study samples. Subjects in both groups had no any history of injury in the past year, no damage to the visual and vestibular systems, and no any neurological disorder and postural abnormalities (e.g. lordosis, flat feet, genu valgum, genu varum). After giving information about the study protocol, an informed consent was obtained from all the participants. The study was conducted in a suitable and quiet place inside the school.
First, a questionnaire of personal information, health and physical activity status was provided to the subjects to ensure that the subjects were prepared to perform balance tests. Then the measurements related to the descriptive information of the subjects and the selected anthropometric parameters were performed. Finally, static and dynamic balance tests were performed in three sessions (Table 1). To reduce the learning effect, each session was performed with a 72-h interval. Romberg test [5], and Sharpened Romberg test [6] were used to evaluate static balance and Timed Up and Go test [7], tandem walk test [8], and Y balance test [9] were used to evaluate dynamic balance in three scoring times. Body height, upper body length, lower body length, foot length and body mass were used as anthropometric factors [10].

Results
The purpose of this study was to evaluate the reliability of functional balance tests and the relationship between these tests and selected anthropometric parameters in girls and boys aged 7-10 years. The results of the present study showed that none of the static balance tests including Romberg test and Sharpened Romberg balance test had the acceptable reliability for girls and boys. Regarding the dynamic balance tests, based on the ICC value, the reliability of timed up and go test and tandem walk test were reliable only for the boys, while Y balance test had the required reliability in both boys and girls. Moreover, the results showed no significant relationship between anthropometric variables and static and dynamic balance tests except between lower body length and Y balance test.

Discussion and Conclusion
It seems that at the age of 7-10 years, static balance tests are affected because the sensory systems related to balance are developing. Therefore, static balance tests, which re-

Compliance with ethical guidelines
All ethical principles were considered in this article.

Funding
The present paper was extracted from the MSc. thesis of the first author, Department of Sports Biomechanics, Faculty of Physical Education and Sports Science, Central Tehran Branch, Islamic Azad University.

Conflicts of interest
The authors declared no conflict of interest.