Extended Abstract
1. Introduction
Daily exercise and activities require postural control known as the ability to monitor body posture and alignment in space and include multilateral analysis of the musculoskeletal and nervous systems [1]. Sensory inputs are one of the basic requirements for postural control in motion systems, so reducing afferent feedback can disrupt the balance, which can lead to an increase in the risk of injury during exercise [2].
The system of monitoring the body posture in space has always attracted the attention of researchers and a lot of research has been conducted on this topic. Results showed that the visual, somatic, and vestibular sensory messages cause proper balance and maintain proper body alignment [1].
Posture is defined as the combination of the position of the joints of the body concerning each other at the same time. The position of each joint will affect the position of the other joints. Proper posture is a situation where the joints and muscle activities are pressed at their lowest. Other situations that put pressure on the joints are commonly referred to as false postures, which consume a lot of energy. Spinal anomalies, rooted from inherited, acquired, and/or unknown causes, affect postural control and disrupt one’s balance [3].
2. Participants and Methods
The research was causal-comparative and its data were quantitatively measured. The statistical population was male undergraduate students (mean age: 21.15±2.02; height: 1.78±0.07; weight: 71.50±10.15; BMI: 2.53±22.45) from the University of Guilan, in the academic year of 2018-2019. The statistical population was selected by random simple sampling from male students of physical education.

Inclusion criteria included no history of defects in the nervous, visual, auditory, and vestibular systems, dizziness, fracture, and/or surgery in the lower extremities and ankle sprains. 40 students were selected as the sample of the study. The selected anthropometric and posture indices included chest width, chest depth, chest circumference, forward head, round shoulder, kyphosis, and lordosis.

 Anthropometric indices were measured using a stadiometer, a digital scale, a flexible tape measure, and a depthometer caliper gauge (to measure chest depth). In addition, a 60 cm flexible ruler, a camera, and the Kinova software were used to measure posture indices, and the Single Leg Stance (SLS) test was used to evaluate the posture control.
Kolmogorov-Smirnov test was used to determine the normal distribution of data. Correlation and regression tests were used for data analysis by SPSS v. 21 software.
3. Results
Table 1 shows the correlations between the mean values ​​of anthropometric indices of posture and postural control of active individuals. Regarding the reported correlations among the predictor, variables with the regression model balance were investigated. Summary results of linear regression test between the criteria variables (balance) and predictor variables (chest depth, head forward, round shoulder) showed that this model was able to predict 22% variance of criterion variable (postural control) with a correlation coefficient of 0.532 and the coefficient of determination 0.283 (Adjusted R Square=0.223) (Table2).
In Table 3, the results of the regression coefficients test also showed that among the predictor variables, two variables of chest depth and head forward were able to significantly predict balance scores. The results of this relationship indicate that there is a positive relationship between the variables of chest depth and head forward and postural control.
4. Discussion
According to the results of this study, there is a weak significant relationship between some anthropometric and postural indices with postural control. Therefore, it seems that anthropometric and postural indices alone cannot affect postural control status of active and healthy male students. Since there is a difference in balance evaluation methods, and anthropometric and postural samples and indices in different studies, it is not possible to sum up a comprehensive conclusion. Also, balance prediction and postural control separately based on factors do not appear to be correct, since balance preservation is the result of the complex interaction of multiple internal and external items and factors such as muscle activity, activated muscle synergy, type of balance strategy, and proprioceptive must also be taken into consideration.
5. Conclusion
Based on the results, none of the anthropometric and postural indices used in this study alone can affect postural control in active and healthy subjects. Therefore, further research is needed to find the relationships of the variables involved in postural control and maintaining balance.
Ethical Considerations
Compliance with ethical guidelines
All ethical principles were considered in this article. The participants were informed about the purpose of the research and its implementation stages; they were also assured about the confidentiality of their information; Moreover, They were allowed to leave the study whenever they wish, and if desired, the results of the research would be available to them.
Funding
This research did not receive any specifc grant from funding agencies in the public, commercial, or not-forproft sectors
Authors' contributions
Conceptualization, methodology, supervision: All authors; Invesigation, writing original draft, funding acquisition, Resources: Hamid Zolghadr; Writing-review and editing: Parisa Sedaghati, Hassan Daneshmandi.
Conflicts of interest
The authors declared no conflict of interes.
Acknowledgements
We would like to thank the research assistant of the University of Guilan and all the subjects who sincerely participated in the present study.